Move throw out of include headers

add_custom_target uninstall causes a clash with the same target in rtmidi (https://github.com/thestk/rtmidi).
"add_custom_target cannot create target "uninstall" because another target with the same name already exists.  The existing target is a custom target created in source directory"

Adds new option YAML_CPP_DISABLE_UNINSTALL 

fixes #1151

---------

Co-authored-by: Megamouse <studienricky89@googlemail.de>
Co-authored-by: Jesse Beder <jbeder+github@gmail.com>

.bazelignore

@@ -0,0 +1 @@
+test/gtest-1.11.0

.github/workflows/build.yml

@@ -0,0 +1,85 @@
+name: Github PR
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+  workflow_dispatch:
+permissions: read-all
+jobs:
+  cmake-build:
+      strategy:
+        fail-fast: false
+        matrix:
+          os: [ubuntu-latest, windows-latest, macos-latest]
+          cxx_standard: [11, 17, 20]
+          build: [static, shared]
+          generator: ["Default Generator", "MinGW Makefiles"]
+          exclude:
+          - os: macos-latest
+            build: shared
+          - os: macos-latest
+            generator: "MinGW Makefiles"
+          - os: ubuntu-latest
+            generator: "MinGW Makefiles"
+      env:
+        YAML_BUILD_SHARED_LIBS: ${{ matrix.build == 'shared' && 'ON' || 'OFF' }}
+        CMAKE_GENERATOR: >-
+          ${{format(matrix.generator != 'Default Generator' && '-G "{0}"' || '', matrix.generator)}}
+      runs-on: ${{ matrix.os }}
+      steps:
+        - uses: actions/checkout@v2
+
+        - name: Get number of CPU cores
+          uses: SimenB/github-actions-cpu-cores@v1
+
+        - name: Build Tests
+          shell: bash
+          run: |
+            cmake ${{ env.CMAKE_GENERATOR }} -S "${{ github.workspace }}" -B build -DCMAKE_CXX_STANDARD=${{ matrix.cxx_standard }} -DYAML_BUILD_SHARED_LIBS=${{ env.YAML_BUILD_SHARED_LIBS }} -DYAML_CPP_BUILD_TESTS=ON
+            cd build && cmake --build . --parallel ${{ steps.cpu-cores.outputs.count }}
+
+        - name: Run Tests
+          shell: bash
+          run: |
+            cd build && ctest -C Debug --output-on-failure --verbose
+
+  bazel-build:
+      strategy:
+        matrix:
+          os: [ubuntu-latest, windows-latest, macos-latest]
+      runs-on: ${{ matrix.os }}
+      steps:
+        - uses: actions/checkout@v2
+
+        - name: Build
+          shell: bash
+          run: |
+            cd "${{ github.workspace }}"
+            bazel build :all
+
+        - name: Test
+          shell: bash
+          run: |
+            cd "${{ github.workspace }}"
+            bazel test test
+
+  bzlmod-build:
+      strategy:
+        matrix:
+          os: [ubuntu-latest, windows-latest, macos-latest]
+      runs-on: ${{ matrix.os }}
+      steps:
+        - uses: actions/checkout@v2
+
+        - name: Build
+          shell: bash
+          run: |
+            cd "${{ github.workspace }}"
+            bazel build --enable_bzlmod :all
+
+        - name: Test
+          shell: bash
+          run: |
+            cd "${{ github.workspace }}"
+            bazel test --enable_bzlmod test

.travis.yml

@@ -1,30 +0,0 @@
-language: c++
-os:
-  - linux
-  - osx
-compiler:
-  - clang
-  - gcc
-before_install:
-  - |
-    if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
-      sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y \
-      && sudo apt-get update -qq \
-      && if [ "$CXX" == "g++" ]; then
-        sudo apt-get install -qq g++-4.7 && export CXX="g++-4.7" CC="gcc-4.7"
-      fi
-    fi
-env:
-  - CTEST_OUTPUT_ON_FAILURE=1
-before_script:
-  - mkdir build
-  - cd build
-  - cmake ..
-  - cd ..
-script:
-  - cmake --build build
-  - cmake --build build --target test
-matrix:
-  exclude:
-  - os: linux
-    compiler: clang

BUILD.bazel

@@ -1,3 +1,9 @@
+yaml_cpp_defines = select({
+    # On Windows, ensure static linking is used.
+    "@platforms//os:windows": ["YAML_CPP_STATIC_DEFINE", "YAML_CPP_NO_CONTRIB"],
+    "//conditions:default": [],
+})
+
 cc_library(
     name = "yaml-cpp_internal",
     visibility = ["//:__subpackages__"],
@@ -11,4 +17,5 @@ cc_library(
     includes = ["include"],
     hdrs = glob(["include/**/*.h"]),
     srcs = glob(["src/**/*.cpp", "src/**/*.h"]),
+    defines = yaml_cpp_defines,
 )

CMakeLists.txt

@@ -1,6 +1,19 @@
-# 3.5 is actually available almost everywhere, but this a good minimum
-cmake_minimum_required(VERSION 3.4)
-project(YAML_CPP VERSION 0.6.3 LANGUAGES CXX)
+# 3.5 is actually available almost everywhere, but this a good minimum.
+# 3.14 as the upper policy limit avoids CMake deprecation warnings.
+cmake_minimum_required(VERSION 3.4...3.14)
+
+# enable MSVC_RUNTIME_LIBRARY target property
+# see https://cmake.org/cmake/help/latest/policy/CMP0091.html
+if(POLICY CMP0091)
+  cmake_policy(SET CMP0091 NEW)
+endif()
+
+project(YAML_CPP VERSION 0.8.0 LANGUAGES CXX)
+
+set(YAML_CPP_MAIN_PROJECT OFF)
+if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
+  set(YAML_CPP_MAIN_PROJECT ON)
+endif()
 
 include(CMakePackageConfigHelpers)
 include(CMakeDependentOption)
@@ -8,36 +21,40 @@ include(CheckCXXCompilerFlag)
 include(GNUInstallDirs)
 include(CTest)
 
-find_program(YAML_CPP_CLANG_FORMAT_EXE NAMES clang-format)
-
 option(YAML_CPP_BUILD_CONTRIB "Enable yaml-cpp contrib in library" ON)
 option(YAML_CPP_BUILD_TOOLS "Enable parse tools" ON)
 option(YAML_BUILD_SHARED_LIBS "Build yaml-cpp shared library" ${BUILD_SHARED_LIBS})
+option(YAML_CPP_INSTALL "Enable generation of yaml-cpp install targets" ${YAML_CPP_MAIN_PROJECT})
+option(YAML_CPP_FORMAT_SOURCE "Format source" ${YAML_CPP_MAIN_PROJECT})
+option(YAML_CPP_DISABLE_UNINSTALL  "Disable uninstallation of yaml-cpp" OFF)
 
 cmake_dependent_option(YAML_CPP_BUILD_TESTS
-  "Enable yaml-cpp tests" ON
-  "BUILD_TESTING;CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR" OFF)
-cmake_dependent_option(YAML_CPP_INSTALL
-  "Enable generation of yaml-cpp install targets" ON
-  "CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR" OFF)
+  "Enable yaml-cpp tests" OFF
+  "BUILD_TESTING;YAML_CPP_MAIN_PROJECT" OFF)
 cmake_dependent_option(YAML_MSVC_SHARED_RT
   "MSVC: Build yaml-cpp with shared runtime libs (/MD)" ON
-  "MSVC" OFF)
+  "CMAKE_SYSTEM_NAME MATCHES Windows" OFF)
+
+if (YAML_CPP_FORMAT_SOURCE)
+    find_program(YAML_CPP_CLANG_FORMAT_EXE NAMES clang-format)
+endif()
 
-set(yaml-cpp-type STATIC)
-set(yaml-cpp-label-postfix "static")
 if (YAML_BUILD_SHARED_LIBS)
   set(yaml-cpp-type SHARED)
   set(yaml-cpp-label-postfix "shared")
+else()
+  set(yaml-cpp-type STATIC)
+  set(yaml-cpp-label-postfix "static")
 endif()
 
 set(build-shared $<BOOL:${YAML_BUILD_SHARED_LIBS}>)
 set(build-windows-dll $<AND:$<BOOL:${CMAKE_HOST_WIN32}>,${build-shared}>)
 set(not-msvc $<NOT:$<CXX_COMPILER_ID:MSVC>>)
+set(msvc-shared_rt $<BOOL:${YAML_MSVC_SHARED_RT}>)
 
 if (NOT DEFINED CMAKE_MSVC_RUNTIME_LIBRARY)
   set(CMAKE_MSVC_RUNTIME_LIBRARY
-    MultiThreaded$<$<CONFIG:Debug>:Debug>$<${build-shared}:DLL>)
+    MultiThreaded$<$<CONFIG:Debug>:Debug>$<${msvc-shared_rt}:DLL>)
 endif()
 
 set(contrib-pattern "src/contrib/*.cpp")
@@ -70,6 +87,10 @@ set_property(TARGET yaml-cpp
   PROPERTY
     CXX_STANDARD_REQUIRED ON)
 
+if (NOT YAML_BUILD_SHARED_LIBS)
+  set_property(TARGET yaml-cpp PROPERTY POSITION_INDEPENDENT_CODE ON)
+endif()
+
 target_include_directories(yaml-cpp
   PUBLIC
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
@@ -83,11 +104,15 @@ if (NOT DEFINED CMAKE_CXX_STANDARD)
       CXX_STANDARD 11)
 endif()
 
+if(YAML_CPP_MAIN_PROJECT)
+  target_compile_options(yaml-cpp
+    PRIVATE
+      $<${not-msvc}:-Wall -Wextra -Wshadow -Weffc++ -Wno-long-long>
+      $<${not-msvc}:-pedantic -pedantic-errors>)
+endif()
+
 target_compile_options(yaml-cpp
   PRIVATE
-    $<${not-msvc}:-Wall -Wextra -Wshadow -Weffc++ -Wno-long-long>
-    $<${not-msvc}:-pedantic -pedantic-errors>
-
     $<$<AND:${backport-msvc-runtime},${msvc-rt-mtd-static}>:-MTd>
     $<$<AND:${backport-msvc-runtime},${msvc-rt-mt-static}>:-MT>
     $<$<AND:${backport-msvc-runtime},${msvc-rt-mtd-dll}>:-MDd>
@@ -100,6 +125,8 @@ target_compile_options(yaml-cpp
     $<$<CXX_COMPILER_ID:MSVC>:/W3 /wd4127 /wd4355>)
 
 target_compile_definitions(yaml-cpp
+  PUBLIC
+    $<$<NOT:$<BOOL:${YAML_BUILD_SHARED_LIBS}>>:YAML_CPP_STATIC_DEFINE>
   PRIVATE
     $<${build-windows-dll}:${PROJECT_NAME}_DLL>
     $<$<NOT:$<BOOL:${YAML_CPP_BUILD_CONTRIB}>>:YAML_CPP_NO_CONTRIB>)
@@ -109,16 +136,24 @@ target_sources(yaml-cpp
     $<$<BOOL:${YAML_CPP_BUILD_CONTRIB}>:${yaml-cpp-contrib-sources}>
     ${yaml-cpp-sources})
 
+if (NOT DEFINED CMAKE_DEBUG_POSTFIX)
+  set(CMAKE_DEBUG_POSTFIX "d")
+endif()
+
 set_target_properties(yaml-cpp PROPERTIES
   VERSION "${PROJECT_VERSION}"
   SOVERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}"
   PROJECT_LABEL "yaml-cpp ${yaml-cpp-label-postfix}"
-  DEBUG_POSTFIX d)
+  DEBUG_POSTFIX "${CMAKE_DEBUG_POSTFIX}")
 
+set(CONFIG_EXPORT_DIR "${CMAKE_INSTALL_LIBDIR}/cmake/yaml-cpp")
+set(EXPORT_TARGETS yaml-cpp)
 configure_package_config_file(
   "${PROJECT_SOURCE_DIR}/yaml-cpp-config.cmake.in"
   "${PROJECT_BINARY_DIR}/yaml-cpp-config.cmake"
-  INSTALL_DESTINATION "${CMAKE_INSTALL_DATADIR}/cmake/yaml-cpp")
+  INSTALL_DESTINATION "${CONFIG_EXPORT_DIR}"
+  PATH_VARS CMAKE_INSTALL_INCLUDEDIR CMAKE_INSTALL_LIBDIR CONFIG_EXPORT_DIR YAML_BUILD_SHARED_LIBS)
+unset(EXPORT_TARGETS)
 
 write_basic_package_version_file(
   "${PROJECT_BINARY_DIR}/yaml-cpp-config-version.cmake"
@@ -127,35 +162,49 @@ write_basic_package_version_file(
 configure_file(yaml-cpp.pc.in yaml-cpp.pc @ONLY)
 
 if (YAML_CPP_INSTALL)
-	install(TARGETS yaml-cpp
+  install(TARGETS yaml-cpp
     EXPORT yaml-cpp-targets
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
     ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
-	install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/
+  install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/
     DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-		FILES_MATCHING PATTERN "*.h")
+                FILES_MATCHING PATTERN "*.h")
   install(EXPORT yaml-cpp-targets
-    DESTINATION "${CMAKE_INSTALL_DATADIR}/cmake/yaml-cpp")
-	install(FILES
-		"${PROJECT_BINARY_DIR}/yaml-cpp-config.cmake"
-		"${PROJECT_BINARY_DIR}/yaml-cpp-config-version.cmake"
-    DESTINATION "${CMAKE_INSTALL_DATADIR}/cmake/yaml-cpp")
+    NAMESPACE yaml-cpp::
+    DESTINATION "${CONFIG_EXPORT_DIR}")
+  install(FILES
+      "${PROJECT_BINARY_DIR}/yaml-cpp-config.cmake"
+      "${PROJECT_BINARY_DIR}/yaml-cpp-config-version.cmake"
+    DESTINATION "${CONFIG_EXPORT_DIR}")
   install(FILES "${PROJECT_BINARY_DIR}/yaml-cpp.pc"
-    DESTINATION ${CMAKE_INSTALL_DATADIR}/pkgconfig)
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
 endif()
+unset(CONFIG_EXPORT_DIR)
 
 if(YAML_CPP_BUILD_TESTS)
-	add_subdirectory(test)
+  add_subdirectory(test)
 endif()
 
 if(YAML_CPP_BUILD_TOOLS)
-	add_subdirectory(util)
+  add_subdirectory(util)
 endif()
 
-if (YAML_CPP_CLANG_FORMAT_EXE)
+if (YAML_CPP_FORMAT_SOURCE AND YAML_CPP_CLANG_FORMAT_EXE)
   add_custom_target(format
     COMMAND clang-format --style=file -i $<TARGET_PROPERTY:yaml-cpp,SOURCES>
+    COMMAND_EXPAND_LISTS
     COMMENT "Running clang-format"
     VERBATIM)
 endif()
+
+# uninstall target
+if(YAML_CPP_INSTALL AND NOT YAML_CPP_DISABLE_UNINSTALL AND NOT TARGET uninstall)
+  configure_file(
+    "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
+    IMMEDIATE @ONLY)
+
+  add_custom_target(uninstall
+    COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
+endif()

CONTRIBUTING.md

@@ -17,7 +17,7 @@ Commit messages should be in the imperative mood, as described in the [Git contr
 
 # Tests
 
-Please verify the tests pass by running the target `tests/run_tests`.
+Please verify the tests pass by running the target `test/yaml-cpp-tests`.
 
 If you are adding functionality, add tests accordingly.
 

MODULE.bazel

@@ -0,0 +1,14 @@
+"""
+yaml-cpp is a YAML parser and emitter in c++ matching the YAML specification.
+"""
+
+module(
+    name = "yaml-cpp",
+    compatibility_level = 1,
+    version = "0.8.0",
+)
+
+bazel_dep(name = "platforms", version = "0.0.7")
+bazel_dep(name = "rules_cc", version = "0.0.8")
+
+bazel_dep(name = "googletest", version = "1.14.0", dev_dependency = True)

README.md

@@ -1,50 +1,46 @@
-# yaml-cpp [![Build Status](https://travis-ci.org/jbeder/yaml-cpp.svg?branch=master)](https://travis-ci.org/jbeder/yaml-cpp) [![Documentation](https://codedocs.xyz/jbeder/yaml-cpp.svg)](https://codedocs.xyz/jbeder/yaml-cpp/)
+# yaml-cpp ![Build Status](https://github.com/jbeder/yaml-cpp/actions/workflows/build.yml/badge.svg) [![Documentation](https://codedocs.xyz/jbeder/yaml-cpp.svg)](https://codedocs.xyz/jbeder/yaml-cpp/)
 
-yaml-cpp is a [YAML](http://www.yaml.org/) parser and emitter in C++ matching the [YAML 1.2 spec](http://www.yaml.org/spec/1.2/spec.html).
+`yaml-cpp` is a [YAML](http://www.yaml.org/) parser and emitter in C++ matching the [YAML 1.2 spec](http://www.yaml.org/spec/1.2/spec.html).
 
-To get a feel for how it can be used, see the [Tutorial](https://github.com/jbeder/yaml-cpp/wiki/Tutorial) or [How to Emit YAML](https://github.com/jbeder/yaml-cpp/wiki/How-To-Emit-YAML). For the old API (version < 0.5.0), see [How To Parse A Document](https://github.com/jbeder/yaml-cpp/wiki/How-To-Parse-A-Document-(Old-API)).
+## Usage
 
-# Problems? #
+See [Tutorial](https://github.com/jbeder/yaml-cpp/wiki/Tutorial) and [How to Emit YAML](https://github.com/jbeder/yaml-cpp/wiki/How-To-Emit-YAML) for reference. For the old API (until 0.5.0), see [How To Parse A Document](https://github.com/jbeder/yaml-cpp/wiki/How-To-Parse-A-Document-(Old-API)).
+
+## Any Problems?
 
 If you find a bug, post an [issue](https://github.com/jbeder/yaml-cpp/issues)! If you have questions about how to use yaml-cpp, please post it on http://stackoverflow.com and tag it [`yaml-cpp`](http://stackoverflow.com/questions/tagged/yaml-cpp).
 
-# How to Build #
+## How to Build
 
-yaml-cpp uses [CMake](http://www.cmake.org) to support cross-platform building. The basic steps to build are:
+`yaml-cpp` uses [CMake](http://www.cmake.org) to support cross-platform building. Install [CMake](http://www.cmake.org) _(Resources -> Download)_ before proceeding. The basic steps to build are:
 
-1. Download and install [CMake](http://www.cmake.org) (Resources -> Download).
+**Note:** If you don't use the provided installer for your platform, make sure that you add `CMake`'s bin folder to your path.
 
-**Note:** If you don't use the provided installer for your platform, make sure that you add CMake's bin folder to your path.
+#### 1. Navigate into the source directory, create build folder and run `CMake`:
 
-2. Navigate into the source directory, and type:
-
-```
+```sh
 mkdir build
 cd build
+cmake [-G generator] [-DYAML_BUILD_SHARED_LIBS=on|OFF] ..
 ```
 
-3. Run CMake. The basic syntax is:
+  * The `generator` option is the build system you'd like to use. Run `cmake` without arguments to see a full list of available generators.
+    * On Windows, you might use "Visual Studio 12 2013" (VS 2013 32-bits), or "Visual Studio 14 2015 Win64" (VS 2015 64-bits).
+    * On OS X, you might use "Xcode".
+    * On a UNIX-like system, omit the option (for a Makefile).
 
-```
-cmake [-G generator] [-DYAML_BUILD_SHARED_LIBS=ON|OFF] ..
-```
-
-  * The `generator` is whatever type of build system you'd like to use. To see a full list of generators on your platform, just run `cmake` (with no arguments). For example:
-    * On Windows, you might use "Visual Studio 12 2013" to generate a Visual Studio 2013 solution or "Visual Studio 14 2015 Win64" to generate a 64-bit Visual Studio 2015 solution.
-    * On OS X, you might use "Xcode" to generate an Xcode project
-    * On a UNIX-y system, simply omit the option to generate a makefile
-
-  * yaml-cpp defaults to building a static library, but you may build a shared library by specifying `-DYAML_BUILD_SHARED_LIBS=ON`.
+  * `yaml-cpp` builds a static library by default, you may want to build a shared library by specifying `-DYAML_BUILD_SHARED_LIBS=ON`.
 
   * For more options on customizing the build, see the [CMakeLists.txt](https://github.com/jbeder/yaml-cpp/blob/master/CMakeLists.txt) file.
 
-4. Build it!
+#### 2. Build it!
+  * The command you'll need to run depends on the generator you chose earlier.
 
-5. To clean up, just remove the `build` directory.
+**Note:** To clean up, just remove the `build` directory.
 
-# Recent Release #
+## Recent Releases
 
-[yaml-cpp 0.6.0](https://github.com/jbeder/yaml-cpp/releases/tag/yaml-cpp-0.6.0) has been released! This release requires C++11, and no longer depends on Boost.
+[yaml-cpp 0.6.0](https://github.com/jbeder/yaml-cpp/releases/tag/yaml-cpp-0.6.0) released! This release requires C++11, and no longer depends on Boost.
 
 [yaml-cpp 0.3.0](https://github.com/jbeder/yaml-cpp/releases/tag/release-0.3.0) is still available if you want the old API.
 
@@ -53,3 +49,10 @@ cmake [-G generator] [-DYAML_BUILD_SHARED_LIBS=ON|OFF] ..
 # API Documentation 
 
 The autogenerated API reference is hosted on [CodeDocs](https://codedocs.xyz/jbeder/yaml-cpp/index.html)
+
+# Third Party Integrations
+
+The following projects are not officially supported:
+
+- [Qt wrapper](https://gist.github.com/brcha/d392b2fe5f1e427cc8a6)
+- [UnrealEngine Wrapper](https://github.com/jwindgassen/UnrealYAML)

SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Supported Versions
+
+Security updates are applied only to the latest release.
+
+## Reporting a Vulnerability
+
+If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released.
+
+Please disclose it at [security advisory](https://github.com/jbeder/yaml-cpp/security/advisories/new).
+
+This project is maintained by a team of volunteers on a reasonable-effort basis. As such, vulnerabilities will be disclosed in a best effort base.

cmake_uninstall.cmake.in

@@ -0,0 +1,21 @@
+if(NOT EXISTS "@CMAKE_BINARY_DIR@/install_manifest.txt")
+  message(FATAL_ERROR "Cannot find install manifest: @CMAKE_BINARY_DIR@/install_manifest.txt")
+endif()
+
+file(READ "@CMAKE_BINARY_DIR@/install_manifest.txt" files)
+string(REGEX REPLACE "\n" ";" files "${files}")
+foreach(file ${files})
+  message(STATUS "Uninstalling $ENV{DESTDIR}${file}")
+  if(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+    exec_program(
+      "@CMAKE_COMMAND@" ARGS "-E remove \"$ENV{DESTDIR}${file}\""
+      OUTPUT_VARIABLE rm_out
+      RETURN_VALUE rm_retval
+      )
+    if(NOT "${rm_retval}" STREQUAL 0)
+      message(FATAL_ERROR "Problem when removing $ENV{DESTDIR}${file}")
+    endif()
+  else(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+    message(STATUS "File $ENV{DESTDIR}${file} does not exist.")
+  endif()
+endforeach()

docs/Breaking-Changes.md

@@ -0,0 +1,52 @@
+# The following is a list of breaking changes to yaml-cpp, by version #
+
+# New API #
+
+## HEAD ##
+
+  * Throws an exception when trying to parse a negative number as an unsigned integer.
+  * Supports the `as<int8_t>`/`as<uint8_t>`, which throws an exception when the value exceeds the range of `int8_t`/`uint8_t`.
+
+## 0.6.0 ##
+
+  * Requires C++11.
+
+## 0.5.3 ##
+
+_none_
+
+## 0.5.2 ##
+
+_none_
+
+## 0.5.1 ##
+
+  * `Node::clear` was replaced by `Node::reset`, which takes an optional node, similar to smart pointers.
+
+## 0.5.0 ##
+
+Initial version of the new API.
+
+# Old API #
+
+## 0.3.0 ##
+
+_none_
+
+## 0.2.7 ##
+
+  * `YAML::Binary` now takes `const unsigned char *` for the binary data (instead of `const char *`).
+
+## 0.2.6 ##
+
+  * `Node::GetType()` is now `Node::Type()`, and returns an enum `NodeType::value`, where:
+> > ` struct NodeType { enum value { Null, Scalar, Sequence, Map }; }; `
+  * `Node::GetTag()` is now `Node::Tag()`
+  * `Node::Identity()` is removed, and `Node::IsAlias()` and `Node::IsReferenced()` have been merged into `Node::IsAliased()`. The reason: there's no reason to distinguish an alias node from its anchor - whichever happens to be emitted first will be the anchor, and the rest will be aliases.
+  * `Node::Read<T>` is now `Node::to<T>`. This wasn't a documented function, so it shouldn't break anything.
+  * `Node`'s comparison operators (for example, `operator == (const Node&, const T&)`) have all been removed. These weren't documented either (they were just used for the tests), so this shouldn't break anything either.
+  * The emitter no longer produces the document start by default - if you want it, you can supply it with the manipulator `YAML::BeginDoc`.
+
+## 0.2.5 ##
+
+This wiki was started with v0.2.5.

docs/How-To-Emit-YAML.md

@@ -0,0 +1,224 @@
+## Contents ##
+
+
+
+# Basic Emitting #
+
+The model for emitting YAML is `std::ostream` manipulators. A `YAML::Emitter` objects acts as an output stream, and its output can be retrieved through the `c_str()` function (as in `std::string`). For a simple example:
+
+```cpp
+#include "yaml-cpp/yaml.h"
+
+int main()
+{
+   YAML::Emitter out;
+   out << "Hello, World!";
+   
+   std::cout << "Here's the output YAML:\n" << out.c_str(); // prints "Hello, World!"
+   return 0;
+}
+```
+
+# Simple Lists and Maps #
+
+A `YAML::Emitter` object acts as a state machine, and we use manipulators to move it between states. Here's a simple sequence:
+
+```cpp
+YAML::Emitter out;
+out << YAML::BeginSeq;
+out << "eggs";
+out << "bread";
+out << "milk";
+out << YAML::EndSeq;
+```
+
+produces
+
+```yaml
+- eggs
+- bread
+- milk
+```
+
+A simple map:
+
+```cpp
+YAML::Emitter out;
+out << YAML::BeginMap;
+out << YAML::Key << "name";
+out << YAML::Value << "Ryan Braun";
+out << YAML::Key << "position";
+out << YAML::Value << "LF";
+out << YAML::EndMap;
+```
+
+produces
+
+```yaml
+name: Ryan Braun
+position: LF
+```
+
+These elements can, of course, be nested:
+
+```cpp
+YAML::Emitter out;
+out << YAML::BeginMap;
+out << YAML::Key << "name";
+out << YAML::Value << "Barack Obama";
+out << YAML::Key << "children";
+out << YAML::Value << YAML::BeginSeq << "Sasha" << "Malia" << YAML::EndSeq;
+out << YAML::EndMap;
+```
+
+produces
+
+```yaml
+name: Barack Obama
+children:
+  - Sasha
+  - Malia
+```
+
+# Using Manipulators #
+
+To deviate from standard formatting, you can use manipulators to modify the output format. For example,
+
+```cpp
+YAML::Emitter out;
+out << YAML::Literal << "A\n B\n  C";
+```
+
+produces
+
+```yaml
+|
+A
+ B
+  C
+```
+and
+
+```cpp
+YAML::Emitter out;
+out << YAML::Flow;
+out << YAML::BeginSeq << 2 << 3 << 5 << 7 << 11 << YAML::EndSeq;
+```
+
+produces
+
+```yaml
+[2, 3, 5, 7, 11]
+```
+
+Comments act like manipulators:
+
+```cpp
+YAML::Emitter out;
+out << YAML::BeginMap;
+out << YAML::Key << "method";
+out << YAML::Value << "least squares";
+out << YAML::Comment("should we change this method?");
+out << YAML::EndMap;
+```
+
+produces
+
+```yaml
+method: least squares  # should we change this method?
+```
+
+And so do aliases/anchors:
+
+```cpp
+YAML::Emitter out;
+out << YAML::BeginSeq;
+out << YAML::Anchor("fred");
+out << YAML::BeginMap;
+out << YAML::Key << "name" << YAML::Value << "Fred";
+out << YAML::Key << "age" << YAML::Value << "42";
+out << YAML::EndMap;
+out << YAML::Alias("fred");
+out << YAML::EndSeq;
+```
+
+produces
+
+```yaml
+- &fred
+  name: Fred
+  age: 42
+- *fred
+```
+
+# STL Containers, and Other Overloads #
+We overload `operator <<` for `std::vector`, `std::list`, and `std::map`, so you can write stuff like:
+
+```cpp
+std::vector <int> squares = {1, 4, 9, 16};
+
+std::map <std::string, int> ages = {{"Daniel", 26}, {"Jesse", 24}};
+
+YAML::Emitter out;
+out << YAML::BeginSeq;
+out << YAML::Flow << squares;
+out << ages;
+out << YAML::EndSeq;
+```
+
+produces
+
+```yaml
+- [1, 4, 9, 16]
+-
+  Daniel: 26
+  Jesse: 24
+```
+
+Of course, you can overload `operator <<` for your own types:
+
+```cpp
+struct Vec3 { int x; int y; int z; };
+YAML::Emitter& operator << (YAML::Emitter& out, const Vec3& v) {
+	out << YAML::Flow;
+	out << YAML::BeginSeq << v.x << v.y << v.z << YAML::EndSeq;
+	return out;
+}
+```
+and it'll play nicely with everything else.
+
+# Using Existing Nodes #
+
+We also overload `operator << ` for `YAML::Node`s in both APIs, so you can output existing Nodes. Of course, Nodes in the old API are read-only, so it's tricky to emit them if you want to modify them. So use the new API!
+
+# Output Encoding #
+
+The output is always UTF-8. By default, yaml-cpp will output as much as it can without escaping any characters. If you want to restrict the output to ASCII, use the manipulator `YAML::EscapeNonAscii`:
+
+```cpp
+emitter.SetOutputCharset(YAML::EscapeNonAscii);
+```
+
+# Lifetime of Manipulators #
+
+Manipulators affect the **next** output item in the stream. If that item is a `BeginSeq` or `BeginMap`, the manipulator lasts until the corresponding `EndSeq` or `EndMap`. (However, within that sequence or map, you can override the manipulator locally, etc.; in effect, there's a "manipulator stack" behind the scenes.)
+
+If you want to permanently change a setting, there are global setters corresponding to each manipulator, e.g.:
+
+```cpp
+YAML::Emitter out;
+out.SetIndent(4);
+out.SetMapStyle(YAML::Flow);
+```
+
+# When Something Goes Wrong #
+
+If something goes wrong when you're emitting a document, it must be something like forgetting a `YAML::EndSeq`, or a misplaced `YAML::Key`. In this case, emitting silently fails (no more output is emitted) and an error flag is set. For example:
+
+```cpp
+YAML::Emitter out;
+assert(out.good());
+out << YAML::Key;
+assert(!out.good());
+std::cout << "Emitter error: " << out.GetLastError() << "\n";
+```

docs/How-To-Parse-A-Document-(Old-API).md

@@ -0,0 +1,265 @@
+_The following describes the old API. For the new API, see the [Tutorial](https://github.com/jbeder/yaml-cpp/wiki/Tutorial)._
+
+## Contents ##
+
+
+# Basic Parsing #
+
+The parser accepts streams, not file names, so you need to first load the file. Since a YAML file can contain many documents, you can grab them one-by-one. A simple way to parse a YAML file might be:
+
+```
+#include <fstream>
+#include "yaml-cpp/yaml.h"
+
+int main()
+{
+    std::ifstream fin("test.yaml");
+    YAML::Parser parser(fin);
+
+    YAML::Node doc;
+    while(parser.GetNextDocument(doc)) {
+       // ...
+    }
+
+    return 0;
+}
+```
+
+# Reading From the Document #
+
+Suppose we have a document consisting only of a scalar. We can read that scalar like this:
+
+```
+YAML::Node doc;    // let's say we've already parsed this document
+std::string scalar;
+doc >> scalar;
+std::cout << "That scalar was: " << scalar << std::endl;
+```
+
+How about sequences? Let's say our document now consists only of a sequences of scalars. We can use an iterator:
+
+```
+YAML::Node doc;    // already parsed
+for(YAML::Iterator it=doc.begin();it!=doc.end();++it) {
+    std::string scalar;
+    *it >> scalar;
+    std::cout << "Found scalar: " << scalar << std::endl;
+}
+```
+
+... or we can just loop through:
+
+```
+YAML::Node doc;    // already parsed
+for(unsigned i=0;i<doc.size();i++) {
+    std::string scalar;
+    doc[i] >> scalar;
+    std::cout << "Found scalar: " << scalar << std::endl;
+}
+```
+
+And finally maps. For now, let's say our document is a map with all keys/values being scalars. Again, we can iterate:
+
+```
+YAML::Node doc;    // already parsed
+for(YAML::Iterator it=doc.begin();it!=doc.end();++it) {
+    std::string key, value;
+    it.first() >> key;
+    it.second() >> value;
+    std::cout << "Key: " << key << ", value: " << value << std::endl;
+}
+```
+
+Note that dereferencing a map iterator is undefined; instead, use the `first` and `second` methods to get the key and value nodes, respectively.
+
+Alternatively, we can pick off the values one-by-one, if we know the keys:
+
+```
+YAML::Node doc;    // already parsed
+std::string name;
+doc["name"] >> name;
+int age;
+doc["age"] >> age;
+std::cout << "Found entry with name '" << name << "' and age '" << age << "'\n";
+```
+
+One thing to be keep in mind: reading a map by key (as immediately above) requires looping through all entries until we find the right key, which is an O(n) operation. So if you're reading the entire map this way, it'll be O(n^2). For small n, this isn't a big deal, but I wouldn't recommend reading maps with a very large number of entries (>100, say) this way.
+
+## Optional Keys ##
+
+If you try to access a key that doesn't exist, `yaml-cpp` throws an exception (see [When Something Goes Wrong](https://github.com/jbeder/yaml-cpp/wiki/How-To-Parse-A-Document-(Old-API)#When_Something_Goes_Wrong). If you have optional keys, it's often easier to use `FindValue` instead of `operator[]`:
+
+```
+YAML::Node doc;    // already parsed
+if(const YAML::Node *pName = doc.FindValue("name")) {
+    std::string name;
+    *pName >> name;
+    std::cout << "Key 'name' exists, with value '" << name << "'\n";
+} else {
+    std::cout << "Key 'name' doesn't exist\n";
+}
+```
+
+# Getting More Complicated #
+
+The above three methods can be combined to read from an arbitrary document. But we can make life a lot easier. Suppose we're reading 3-vectors (i.e., vectors with three components), so we've got a structure looking like this:
+
+```
+struct Vec3 {
+    float x, y, z;
+};
+```
+
+We can read this in one operation by overloading the extraction (>>) operator:
+
+```
+void operator >> (const YAML::Node& node, Vec3& v)
+{
+    node[0] >> v.x;
+    node[1] >> v.y;
+    node[2] >> v.z;
+}
+
+// now it's a piece of cake to read it
+YAML::Node doc;    // already parsed
+Vec3 v;
+doc >> v;
+std::cout << "Here's the vector: (" << v.x << ", " << v.y << ", " << v.z << ")\n";
+```
+
+# A Complete Example #
+
+Here's a complete example of how to parse a complex YAML file:
+
+`monsters.yaml`
+
+```
+- name: Ogre
+  position: [0, 5, 0]
+  powers:
+    - name: Club
+      damage: 10
+    - name: Fist
+      damage: 8
+- name: Dragon
+  position: [1, 0, 10]
+  powers:
+    - name: Fire Breath
+      damage: 25
+    - name: Claws
+      damage: 15
+- name: Wizard
+  position: [5, -3, 0]
+  powers:
+    - name: Acid Rain
+      damage: 50
+    - name: Staff
+      damage: 3
+```
+
+`main.cpp`
+
+```
+#include "yaml-cpp/yaml.h"
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <vector>
+
+// our data types
+struct Vec3 {
+   float x, y, z;
+};
+
+struct Power {
+   std::string name;
+   int damage;
+};
+
+struct Monster {
+   std::string name;
+   Vec3 position;
+   std::vector <Power> powers;
+};
+
+// now the extraction operators for these types
+void operator >> (const YAML::Node& node, Vec3& v) {
+   node[0] >> v.x;
+   node[1] >> v.y;
+   node[2] >> v.z;
+}
+
+void operator >> (const YAML::Node& node, Power& power) {
+   node["name"] >> power.name;
+   node["damage"] >> power.damage;
+}
+
+void operator >> (const YAML::Node& node, Monster& monster) {
+   node["name"] >> monster.name;
+   node["position"] >> monster.position;
+   const YAML::Node& powers = node["powers"];
+   for(unsigned i=0;i<powers.size();i++) {
+      Power power;
+      powers[i] >> power;
+      monster.powers.push_back(power);
+   }
+}
+
+int main()
+{
+   std::ifstream fin("monsters.yaml");
+   YAML::Parser parser(fin);
+   YAML::Node doc;
+   parser.GetNextDocument(doc);
+   for(unsigned i=0;i<doc.size();i++) {
+      Monster monster;
+      doc[i] >> monster;
+      std::cout << monster.name << "\n";
+   }
+
+   return 0;
+}
+```
+
+# When Something Goes Wrong #
+
+... we throw an exception (all exceptions are derived from `YAML::Exception`). If there's a parsing exception (i.e., a malformed YAML document), we throw a `YAML::ParserException`:
+
+```
+try {
+    std::ifstream fin("test.yaml");
+    YAML::Parser parser(fin);
+    YAML::Node doc;
+    parser.GetNextDocument(doc);
+    // do stuff
+} catch(YAML::ParserException& e) {
+    std::cout << e.what() << "\n";
+}
+```
+
+If you make a programming error (say, trying to read a scalar from a sequence node, or grabbing a key that doesn't exist), we throw some kind of `YAML::RepresentationException`. To prevent this, you can check what kind of node something is:
+
+```
+    YAML::Node node;
+    YAML::NodeType::value type = node.Type();  // should be:
+                                               // YAML::NodeType::Null
+                                               // YAML::NodeType::Scalar
+                                               // YAML::NodeType::Sequence
+                                               // YAML::NodeType::Map
+```
+
+# Note about copying `YAML::Node` #
+
+Currently `YAML::Node` is non-copyable, so you need to do something like
+
+```
+    const YAML::Node& node = doc["whatever"];
+```
+
+This is intended behavior. If you want to copy a node, use the `Clone` function:
+
+```
+    std::auto_ptr<YAML::Node> pCopy = myOtherNode.Clone();
+```
+
+The intent is that if you'd like to keep a `YAML::Node` around for longer than the document will stay in scope, you can clone it and store it as long as you like.

docs/Strings.md

@@ -0,0 +1,18 @@
+# Encodings and `yaml-cpp` #
+
+`yaml-cpp` will parse any file as specified by the [YAML 1.2 spec](http://www.yaml.org/spec/1.2/spec.html#id2570322). Internally, it stores all strings in UTF-8, and representation is done with UTF-8. This means that in
+
+```
+std::string str;
+node >> str;
+```
+
+`str` will be UTF-8. Similarly, if you're accessing a map by string key, you need to pass the key in UTF-8. If your application uses a different encoding, you need to convert to and from UTF-8 to work with `yaml-cpp`. (It's possible we'll add some small conversion functions, but for now it's restricted.)
+
+---
+
+For convenience, Richard Weeks has kindly provided a google gadget that converts Unicode to a string literal. It's a Google Gadget, so unfortunately it does not work on GitHub. Patches welcome to port it to a usable format here:
+
+```
+<wiki:gadget url="http://hosting.gmodules.com/ig/gadgets/file/111180078345548400783/c-style-utf8-encoder.xml"/>
+```

docs/Tutorial.md

@@ -0,0 +1,201 @@
+# Introduction #
+
+A typical example, loading a configuration file, might look like this:
+
+```cpp
+YAML::Node config = YAML::LoadFile("config.yaml");
+
+if (config["lastLogin"]) {
+  std::cout << "Last logged in: " << config["lastLogin"].as<DateTime>() << "\n";
+}
+
+const std::string username = config["username"].as<std::string>();
+const std::string password = config["password"].as<std::string>();
+login(username, password);
+config["lastLogin"] = getCurrentDateTime();
+
+std::ofstream fout("config.yaml");
+fout << config;
+```
+
+# Basic Parsing and Node Editing #
+
+All nodes in a YAML document (including the root) are represented by `YAML::Node`. You can check what kind it is:
+
+```cpp
+YAML::Node node = YAML::Load("[1, 2, 3]");
+assert(node.Type() == YAML::NodeType::Sequence);
+assert(node.IsSequence());  // a shortcut!
+```
+
+Collection nodes (sequences and maps) act somewhat like STL vectors and maps:
+
+```cpp
+YAML::Node primes = YAML::Load("[2, 3, 5, 7, 11]");
+for (std::size_t i=0;i<primes.size();i++) {
+  std::cout << primes[i].as<int>() << "\n";
+}
+// or:
+for (YAML::const_iterator it=primes.begin();it!=primes.end();++it) {
+  std::cout << it->as<int>() << "\n";
+}
+
+primes.push_back(13);
+assert(primes.size() == 6);
+```
+
+and
+
+```cpp
+YAML::Node lineup = YAML::Load("{1B: Prince Fielder, 2B: Rickie Weeks, LF: Ryan Braun}");
+for(YAML::const_iterator it=lineup.begin();it!=lineup.end();++it) {
+  std::cout << "Playing at " << it->first.as<std::string>() << " is " << it->second.as<std::string>() << "\n";
+}
+
+lineup["RF"] = "Corey Hart";
+lineup["C"] = "Jonathan Lucroy";
+assert(lineup.size() == 5);
+```
+
+Querying for keys does **not** create them automatically (this makes handling optional map entries very easy)
+
+```cpp
+YAML::Node node = YAML::Load("{name: Brewers, city: Milwaukee}");
+if (node["name"]) {
+  std::cout << node["name"].as<std::string>() << "\n";
+}
+if (node["mascot"]) {
+  std::cout << node["mascot"].as<std::string>() << "\n";
+}
+assert(node.size() == 2); // the previous call didn't create a node
+```
+
+If you're not sure what kind of data you're getting, you can query the type of a node:
+
+```cpp
+switch (node.Type()) {
+  case Null: // ...
+  case Scalar: // ...
+  case Sequence: // ...
+  case Map: // ...
+  case Undefined: // ...
+}
+```
+
+or ask directly whether it's a particular type, e.g.:
+
+```cpp
+if (node.IsSequence()) {
+  // ...
+}
+```
+
+# Building Nodes #
+
+You can build `YAML::Node` from scratch:
+
+```cpp
+YAML::Node node;  // starts out as null
+node["key"] = "value";  // it now is a map node
+node["seq"].push_back("first element");  // node["seq"] automatically becomes a sequence
+node["seq"].push_back("second element");
+
+node["mirror"] = node["seq"][0];  // this creates an alias
+node["seq"][0] = "1st element";  // this also changes node["mirror"]
+node["mirror"] = "element #1";  // and this changes node["seq"][0] - they're really the "same" node
+
+node["self"] = node;  // you can even create self-aliases
+node[node["mirror"]] = node["seq"];  // and strange loops :)
+```
+
+The above node is now:
+
+```yaml
+&1
+key: value
+&2 seq: [&3 "element #1", second element]
+mirror: *3
+self: *1
+*3 : *2
+```
+
+# How Sequences Turn Into Maps #
+
+Sequences can be turned into maps by asking for non-integer keys. For example,
+
+```cpp
+YAML::Node node  = YAML::Load("[1, 2, 3]");
+node[1] = 5;  // still a sequence, [1, 5, 3]
+node.push_back(-3) // still a sequence, [1, 5, 3, -3]
+node["key"] = "value"; // now it's a map! {0: 1, 1: 5, 2: 3, 3: -3, key: value}
+```
+
+Indexing a sequence node by an index that's not in its range will _usually_ turn it into a map, but if the index is one past the end of the sequence, then the sequence will grow by one to accommodate it. (That's the **only** exception to this rule.) For example,
+
+```cpp
+YAML::Node node = YAML::Load("[1, 2, 3]");
+node[3] = 4; // still a sequence, [1, 2, 3, 4]
+node[10] = 10;  // now it's a map! {0: 1, 1: 2, 2: 3, 3: 4, 10: 10}
+```
+
+# Converting To/From Native Data Types #
+
+Yaml-cpp has built-in conversion to and from most built-in data types, as well as `std::vector`, `std::list`, and `std::map`. The following examples demonstrate when those conversions are used:
+
+```cpp
+YAML::Node node = YAML::Load("{pi: 3.14159, [0, 1]: integers}");
+
+// this needs the conversion from Node to double
+double pi = node["pi"].as<double>();
+
+// this needs the conversion from double to Node
+node["e"] = 2.71828;
+
+// this needs the conversion from Node to std::vector<int> (*not* the other way around!)
+std::vector<int> v;
+v.push_back(0);
+v.push_back(1);
+std::string str = node[v].as<std::string>();
+```
+
+To use yaml-cpp with your own data types, you need to specialize the YAML::convert<> template class. For example, suppose you had a simple `Vec3` class:
+
+```cpp
+struct Vec3 { double x, y, z; /* etc - make sure you have overloaded operator== */ };
+```
+
+You could write
+
+```cpp
+namespace YAML {
+template<>
+struct convert<Vec3> {
+  static Node encode(const Vec3& rhs) {
+    Node node;
+    node.push_back(rhs.x);
+    node.push_back(rhs.y);
+    node.push_back(rhs.z);
+    return node;
+  }
+
+  static bool decode(const Node& node, Vec3& rhs) {
+    if(!node.IsSequence() || node.size() != 3) {
+      return false;
+    }
+
+    rhs.x = node[0].as<double>();
+    rhs.y = node[1].as<double>();
+    rhs.z = node[2].as<double>();
+    return true;
+  }
+};
+}
+```
+
+Then you could use `Vec3` wherever you could use any other type:
+
+```cpp
+YAML::Node node = YAML::Load("start: [1, 3, 0]");
+Vec3 v = node["start"].as<Vec3>();
+node["end"] = Vec3(2, -1, 0);
+```

docs/_config.yml

@@ -0,0 +1 @@
+theme: jekyll-theme-slate

docs/index.md

@@ -0,0 +1 @@
+To learn how to use the library, see the [Tutorial](https://github.com/jbeder/yaml-cpp/wiki/Tutorial) and [How To Emit YAML](https://github.com/jbeder/yaml-cpp/wiki/How-To-Emit-YAML)

include/yaml-cpp/depthguard.h

@@ -0,0 +1,77 @@
+#ifndef DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000
+#define DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000
+
+#if defined(_MSC_VER) ||                                            \
+    (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \
+     (__GNUC__ >= 4))  // GCC supports "pragma once" correctly since 3.4
+#pragma once
+#endif
+
+#include "exceptions.h"
+
+namespace YAML {
+
+/**
+ * @brief The DeepRecursion class
+ *  An exception class which is thrown by DepthGuard. Ideally it should be
+ * a member of DepthGuard. However, DepthGuard is a templated class which means
+ * that any catch points would then need to know the template parameters. It is
+ * simpler for clients to not have to know at the catch point what was the
+ * maximum depth.
+ */
+class DeepRecursion : public ParserException {
+public:
+  virtual ~DeepRecursion() = default;
+
+  DeepRecursion(int depth, const Mark& mark_, const std::string& msg_);
+
+  // Returns the recursion depth when the exception was thrown
+  int depth() const {
+    return m_depth;
+  }
+
+private:
+  int m_depth = 0;
+};
+
+/**
+ * @brief The DepthGuard class
+ *  DepthGuard takes a reference to an integer. It increments the integer upon
+ * construction of DepthGuard and decrements the integer upon destruction.
+ *
+ * If the integer would be incremented past max_depth, then an exception is
+ * thrown. This is ideally geared toward guarding against deep recursion.
+ *
+ * @param max_depth
+ *  compile-time configurable maximum depth.
+ */
+template <int max_depth = 2000>
+class DepthGuard final {
+public:
+  DepthGuard(int & depth_, const Mark& mark_, const std::string& msg_) : m_depth(depth_) {
+    ++m_depth;
+    if ( max_depth <= m_depth ) {
+        throw DeepRecursion{m_depth, mark_, msg_};
+    }
+  }
+
+  DepthGuard(const DepthGuard & copy_ctor) = delete;
+  DepthGuard(DepthGuard && move_ctor) = delete;
+  DepthGuard & operator=(const DepthGuard & copy_assign) = delete;
+  DepthGuard & operator=(DepthGuard && move_assign) = delete;
+
+  ~DepthGuard() {
+    --m_depth;
+  }
+
+  int current_depth() const {
+    return m_depth;
+  }
+
+private:
+    int & m_depth;
+};
+
+} // namespace YAML
+
+#endif // DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000

include/yaml-cpp/dll.h

@@ -1,33 +1,61 @@
 #ifndef DLL_H_62B23520_7C8E_11DE_8A39_0800200C9A66
 #define DLL_H_62B23520_7C8E_11DE_8A39_0800200C9A66
 
-#if defined(_MSC_VER) ||                                            \
-    (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \
-     (__GNUC__ >= 4))  // GCC supports "pragma once" correctly since 3.4
-#pragma once
+// Definition YAML_CPP_STATIC_DEFINE using to building YAML-CPP as static
+// library (definition created by CMake or defined manually)
+
+// Definition yaml_cpp_EXPORTS using to building YAML-CPP as dll/so library
+// (definition created by CMake or defined manually)
+
+#ifdef YAML_CPP_STATIC_DEFINE
+#  define YAML_CPP_API
+#  define YAML_CPP_NO_EXPORT
+#else
+#  if defined(_MSC_VER) || defined(__MINGW32__) || defined(__MINGW64__)
+#    ifndef YAML_CPP_API
+#      ifdef yaml_cpp_EXPORTS
+         /* We are building this library */
+#        pragma message( "Defining YAML_CPP_API for DLL export" )
+#        define YAML_CPP_API __declspec(dllexport)
+#      else
+         /* We are using this library */
+#        pragma message( "Defining YAML_CPP_API for DLL import" )
+#        define YAML_CPP_API __declspec(dllimport)
+#      endif
+#    endif
+#    ifndef YAML_CPP_NO_EXPORT
+#      define YAML_CPP_NO_EXPORT
+#    endif
+#  else /* No _MSC_VER */
+#    ifndef YAML_CPP_API
+#      ifdef yaml_cpp_EXPORTS
+         /* We are building this library */
+#        define YAML_CPP_API __attribute__((visibility("default")))
+#      else
+         /* We are using this library */
+#        define YAML_CPP_API __attribute__((visibility("default")))
+#      endif
+#    endif
+#    ifndef YAML_CPP_NO_EXPORT
+#      define YAML_CPP_NO_EXPORT __attribute__((visibility("hidden")))
+#    endif
+#  endif /* _MSC_VER */
+#endif   /* YAML_CPP_STATIC_DEFINE */
+
+#ifndef YAML_CPP_DEPRECATED
+#  ifdef _MSC_VER
+#    define YAML_CPP_DEPRECATED __declspec(deprecated)
+#  else
+#    define YAML_CPP_DEPRECATED __attribute__ ((__deprecated__))
+#  endif
 #endif
 
-// The following ifdef block is the standard way of creating macros which make
-// exporting from a DLL simpler. All files within this DLL are compiled with the
-// yaml_cpp_EXPORTS symbol defined on the command line. This symbol should not
-// be defined on any project that uses this DLL. This way any other project
-// whose source files include this file see YAML_CPP_API functions as being
-// imported from a DLL, whereas this DLL sees symbols defined with this macro as
-// being exported.
-#undef YAML_CPP_API
+#ifndef YAML_CPP_DEPRECATED_EXPORT
+#  define YAML_CPP_DEPRECATED_EXPORT YAML_CPP_API YAML_CPP_DEPRECATED
+#endif
 
-#ifdef YAML_CPP_DLL      // Using or Building YAML-CPP DLL (definition defined
-                         // manually)
-#ifdef yaml_cpp_EXPORTS  // Building YAML-CPP DLL (definition created by CMake
-                         // or defined manually)
-//	#pragma message( "Defining YAML_CPP_API for DLL export" )
-#define YAML_CPP_API __declspec(dllexport)
-#else  // yaml_cpp_EXPORTS
-//	#pragma message( "Defining YAML_CPP_API for DLL import" )
-#define YAML_CPP_API __declspec(dllimport)
-#endif  // yaml_cpp_EXPORTS
-#else   // YAML_CPP_DLL
-#define YAML_CPP_API
-#endif  // YAML_CPP_DLL
+#ifndef YAML_CPP_DEPRECATED_NO_EXPORT
+#  define YAML_CPP_DEPRECATED_NO_EXPORT YAML_CPP_NO_EXPORT YAML_CPP_DEPRECATED
+#endif
 
-#endif  // DLL_H_62B23520_7C8E_11DE_8A39_0800200C9A66
+#endif /* DLL_H_62B23520_7C8E_11DE_8A39_0800200C9A66 */

include/yaml-cpp/emitter.h

@@ -50,6 +50,7 @@ class YAML_CPP_API Emitter {
   bool SetOutputCharset(EMITTER_MANIP value);
   bool SetStringFormat(EMITTER_MANIP value);
   bool SetBoolFormat(EMITTER_MANIP value);
+  bool SetNullFormat(EMITTER_MANIP value);
   bool SetIntBase(EMITTER_MANIP value);
   bool SetSeqFormat(EMITTER_MANIP value);
   bool SetMapFormat(EMITTER_MANIP value);
@@ -58,6 +59,7 @@ class YAML_CPP_API Emitter {
   bool SetPostCommentIndent(std::size_t n);
   bool SetFloatPrecision(std::size_t n);
   bool SetDoublePrecision(std::size_t n);
+  void RestoreGlobalModifiedSettings();
 
   // local setters
   Emitter& SetLocalValue(EMITTER_MANIP value);
@@ -123,6 +125,7 @@ class YAML_CPP_API Emitter {
   void SpaceOrIndentTo(bool requireSpace, std::size_t indent);
 
   const char* ComputeFullBoolName(bool b) const;
+  const char* ComputeNullName() const;
   bool CanEmitNewline() const;
 
  private:

include/yaml-cpp/emittermanip.h

@@ -19,6 +19,7 @@ enum EMITTER_MANIP {
   // output character set
   EmitNonAscii,
   EscapeNonAscii,
+  EscapeAsJson,
 
   // string manipulators
   // Auto, // duplicate
@@ -26,6 +27,12 @@ enum EMITTER_MANIP {
   DoubleQuoted,
   Literal,
 
+  // null manipulators
+  LowerNull,
+  UpperNull,
+  CamelNull,
+  TildeNull,
+
   // bool manipulators
   YesNoBool,      // yes, no
   TrueFalseBool,  // true, false

include/yaml-cpp/exceptions.h

@@ -65,7 +65,7 @@ const char* const ZERO_INDENT_IN_BLOCK =
 const char* const CHAR_IN_BLOCK = "unexpected character in block scalar";
 const char* const AMBIGUOUS_ANCHOR =
     "cannot assign the same alias to multiple nodes";
-const char* const UNKNOWN_ANCHOR = "the referenced anchor is not defined";
+const char* const UNKNOWN_ANCHOR = "the referenced anchor is not defined: ";
 
 const char* const INVALID_NODE =
     "invalid node; this may result from using a map iterator as a sequence "
@@ -100,6 +100,12 @@ inline const std::string KEY_NOT_FOUND_WITH_KEY(const std::string& key) {
   return stream.str();
 }
 
+inline const std::string KEY_NOT_FOUND_WITH_KEY(const char* key) {
+  std::stringstream stream;
+  stream << KEY_NOT_FOUND << ": " << key;
+  return stream.str();
+}
+
 template <typename T>
 inline const std::string KEY_NOT_FOUND_WITH_KEY(
     const T& key, typename enable_if<is_numeric<T>>::type* = 0) {
@@ -120,6 +126,12 @@ inline const std::string BAD_SUBSCRIPT_WITH_KEY(const std::string& key) {
   return stream.str();
 }
 
+inline const std::string BAD_SUBSCRIPT_WITH_KEY(const char* key) {
+  std::stringstream stream;
+  stream << BAD_SUBSCRIPT << " (key: \"" << key << "\")";
+  return stream.str();
+}
+
 template <typename T>
 inline const std::string BAD_SUBSCRIPT_WITH_KEY(
     const T& key, typename enable_if<is_numeric<T>>::type* = nullptr) {
@@ -136,7 +148,7 @@ inline const std::string INVALID_NODE_WITH_KEY(const std::string& key) {
   stream << "invalid node; first invalid key: \"" << key << "\"";
   return stream.str();
 }
-}
+}  // namespace ErrorMsg
 
 class YAML_CPP_API Exception : public std::runtime_error {
  public:
@@ -248,9 +260,8 @@ class YAML_CPP_API BadDereference : public RepresentationException {
 class YAML_CPP_API BadSubscript : public RepresentationException {
  public:
   template <typename Key>
-  BadSubscript(const Key& key)
-      : RepresentationException(Mark::null_mark(),
-                                ErrorMsg::BAD_SUBSCRIPT_WITH_KEY(key)) {}
+  BadSubscript(const Mark& mark_, const Key& key)
+      : RepresentationException(mark_, ErrorMsg::BAD_SUBSCRIPT_WITH_KEY(key)) {}
   BadSubscript(const BadSubscript&) = default;
   ~BadSubscript() YAML_CPP_NOEXCEPT override;
 };
@@ -281,10 +292,12 @@ class YAML_CPP_API EmitterException : public Exception {
 
 class YAML_CPP_API BadFile : public Exception {
  public:
-  BadFile() : Exception(Mark::null_mark(), ErrorMsg::BAD_FILE) {}
+  explicit BadFile(const std::string& filename)
+      : Exception(Mark::null_mark(),
+                  std::string(ErrorMsg::BAD_FILE) + ": " + filename) {}
   BadFile(const BadFile&) = default;
   ~BadFile() YAML_CPP_NOEXCEPT override;
 };
-}
+}  // namespace YAML
 
 #endif  // EXCEPTIONS_H_62B23520_7C8E_11DE_8A39_0800200C9A66

include/yaml-cpp/node/convert.h

@@ -12,10 +12,16 @@
 #include <limits>
 #include <list>
 #include <map>
+#include <unordered_map>
 #include <sstream>
 #include <type_traits>
+#include <valarray>
 #include <vector>
 
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
+#include <string_view>
+#endif
+
 #include "yaml-cpp/binary.h"
 #include "yaml-cpp/node/impl.h"
 #include "yaml-cpp/node/iterator.h"
@@ -23,6 +29,7 @@
 #include "yaml-cpp/node/type.h"
 #include "yaml-cpp/null.h"
 
+
 namespace YAML {
 class Binary;
 struct _Null;
@@ -73,14 +80,33 @@ struct convert<std::string> {
 // C-strings can only be encoded
 template <>
 struct convert<const char*> {
-  static Node encode(const char*& rhs) { return Node(rhs); }
+  static Node encode(const char* rhs) { return Node(rhs); }
+};
+
+template <>
+struct convert<char*> {
+  static Node encode(const char* rhs) { return Node(rhs); }
 };
 
 template <std::size_t N>
-struct convert<const char[N]> {
-  static Node encode(const char(&rhs)[N]) { return Node(rhs); }
+struct convert<char[N]> {
+  static Node encode(const char* rhs) { return Node(rhs); }
 };
 
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
+template <>
+struct convert<std::string_view> {
+  static Node encode(std::string_view rhs) { return Node(std::string(rhs)); }
+
+  static bool decode(const Node& node, std::string_view& rhs) {
+    if (!node.IsScalar())
+      return false;
+    rhs = node.Scalar();
+    return true;
+  }
+};
+#endif
+
 template <>
 struct convert<_Null> {
   static Node encode(const _Null& /* rhs */) { return Node(); }
@@ -90,27 +116,63 @@ struct convert<_Null> {
   }
 };
 
+namespace conversion {
+template <typename T>
+typename std::enable_if< std::is_floating_point<T>::value, void>::type
+inner_encode(const T& rhs, std::stringstream& stream){
+  if (std::isnan(rhs)) {
+    stream << ".nan";
+  } else if (std::isinf(rhs)) {
+    if (std::signbit(rhs)) {
+      stream << "-.inf";
+    } else {
+      stream << ".inf";
+    }
+  } else {
+    stream << rhs;
+  }
+}
+
+template <typename T>
+typename std::enable_if<!std::is_floating_point<T>::value, void>::type
+inner_encode(const T& rhs, std::stringstream& stream){
+  stream << rhs;
+}
+
+template <typename T>
+typename std::enable_if<(std::is_same<T, unsigned char>::value ||
+                         std::is_same<T, signed char>::value), bool>::type
+ConvertStreamTo(std::stringstream& stream, T& rhs) {
+  int num;
+  if ((stream >> std::noskipws >> num) && (stream >> std::ws).eof()) {
+    if (num >= (std::numeric_limits<T>::min)() &&
+        num <= (std::numeric_limits<T>::max)()) {
+      rhs = static_cast<T>(num);
+      return true;
+    }
+  }
+  return false;
+}
+
+template <typename T>
+typename std::enable_if<!(std::is_same<T, unsigned char>::value ||
+                          std::is_same<T, signed char>::value), bool>::type
+ConvertStreamTo(std::stringstream& stream, T& rhs) {
+  if ((stream >> std::noskipws >> rhs) && (stream >> std::ws).eof()) {
+    return true;
+  }
+  return false;
+}
+}
+
 #define YAML_DEFINE_CONVERT_STREAMABLE(type, negative_op)                  \
   template <>                                                              \
   struct convert<type> {                                                   \
+                                                                           \
     static Node encode(const type& rhs) {                                  \
       std::stringstream stream;                                            \
       stream.precision(std::numeric_limits<type>::max_digits10);           \
-      if (std::is_floating_point<type>::value) {                           \
-        if (std::isnan(rhs)) {                                             \
-          stream << ".nan";                                                \
-        } else if (std::isinf(rhs)) {                                      \
-          if (std::signbit(rhs)) {                                         \
-            stream << "-.inf";                                             \
-          } else {                                                         \
-            stream << ".inf";                                              \
-          }                                                                \
-        } else {                                                           \
-          stream << rhs;                                                   \
-        }                                                                  \
-      } else {                                                             \
-        stream << rhs;                                                     \
-      }                                                                    \
+      conversion::inner_encode(rhs, stream);                               \
       return Node(stream.str());                                           \
     }                                                                      \
                                                                            \
@@ -121,7 +183,10 @@ struct convert<_Null> {
       const std::string& input = node.Scalar();                            \
       std::stringstream stream(input);                                     \
       stream.unsetf(std::ios::dec);                                        \
-      if ((stream >> std::noskipws >> rhs) && (stream >> std::ws).eof()) { \
+      if ((stream.peek() == '-') && std::is_unsigned<type>::value) {       \
+        return false;                                                      \
+      }                                                                    \
+      if (conversion::ConvertStreamTo(stream, rhs)) {                      \
         return true;                                                       \
       }                                                                    \
       if (std::numeric_limits<type>::has_infinity) {                       \
@@ -181,81 +246,104 @@ struct convert<bool> {
 };
 
 // std::map
-template <typename K, typename V>
-struct convert<std::map<K, V>> {
-  static Node encode(const std::map<K, V>& rhs) {
+template <typename K, typename V, typename C, typename A>
+struct convert<std::map<K, V, C, A>> {
+  static Node encode(const std::map<K, V, C, A>& rhs) {
     Node node(NodeType::Map);
-    for (typename std::map<K, V>::const_iterator it = rhs.begin();
-         it != rhs.end(); ++it)
-      node.force_insert(it->first, it->second);
+    for (const auto& element : rhs)
+      node.force_insert(element.first, element.second);
     return node;
   }
 
-  static bool decode(const Node& node, std::map<K, V>& rhs) {
+  static bool decode(const Node& node, std::map<K, V, C, A>& rhs) {
     if (!node.IsMap())
       return false;
 
     rhs.clear();
-    for (const_iterator it = node.begin(); it != node.end(); ++it)
+    for (const auto& element : node)
 #if defined(__GNUC__) && __GNUC__ < 4
       // workaround for GCC 3:
-      rhs[it->first.template as<K>()] = it->second.template as<V>();
+      rhs[element.first.template as<K>()] = element.second.template as<V>();
 #else
-      rhs[it->first.as<K>()] = it->second.as<V>();
+      rhs[element.first.as<K>()] = element.second.as<V>();
+#endif
+    return true;
+  }
+};
+
+// std::unordered_map
+template <typename K, typename V, typename H, typename P, typename A>
+struct convert<std::unordered_map<K, V, H, P, A>> {
+  static Node encode(const std::unordered_map<K, V, H, P, A>& rhs) {
+    Node node(NodeType::Map);
+    for (const auto& element : rhs)
+      node.force_insert(element.first, element.second);
+    return node;
+  }
+
+  static bool decode(const Node& node, std::unordered_map<K, V, H, P, A>& rhs) {
+    if (!node.IsMap())
+      return false;
+
+    rhs.clear();
+    for (const auto& element : node)
+#if defined(__GNUC__) && __GNUC__ < 4
+      // workaround for GCC 3:
+      rhs[element.first.template as<K>()] = element.second.template as<V>();
+#else
+      rhs[element.first.as<K>()] = element.second.as<V>();
 #endif
     return true;
   }
 };
 
 // std::vector
-template <typename T>
-struct convert<std::vector<T>> {
-  static Node encode(const std::vector<T>& rhs) {
+template <typename T, typename A>
+struct convert<std::vector<T, A>> {
+  static Node encode(const std::vector<T, A>& rhs) {
     Node node(NodeType::Sequence);
-    for (typename std::vector<T>::const_iterator it = rhs.begin();
-         it != rhs.end(); ++it)
-      node.push_back(*it);
+    for (const auto& element : rhs)
+      node.push_back(element);
     return node;
   }
 
-  static bool decode(const Node& node, std::vector<T>& rhs) {
+  static bool decode(const Node& node, std::vector<T, A>& rhs) {
     if (!node.IsSequence())
       return false;
 
     rhs.clear();
-    for (const_iterator it = node.begin(); it != node.end(); ++it)
+    for (const auto& element : node)
 #if defined(__GNUC__) && __GNUC__ < 4
       // workaround for GCC 3:
-      rhs.push_back(it->template as<T>());
+      rhs.push_back(element.template as<T>());
 #else
-      rhs.push_back(it->as<T>());
+      rhs.push_back(element.as<T>());
 #endif
     return true;
   }
 };
 
 // std::list
-template <typename T>
-struct convert<std::list<T>> {
-  static Node encode(const std::list<T>& rhs) {
+template <typename T, typename A>
+struct convert<std::list<T,A>> {
+  static Node encode(const std::list<T,A>& rhs) {
     Node node(NodeType::Sequence);
-    for (typename std::list<T>::const_iterator it = rhs.begin();
-         it != rhs.end(); ++it)
-      node.push_back(*it);
+    for (const auto& element : rhs)
+      node.push_back(element);
     return node;
   }
 
-  static bool decode(const Node& node, std::list<T>& rhs) {
+  static bool decode(const Node& node, std::list<T,A>& rhs) {
     if (!node.IsSequence())
       return false;
 
     rhs.clear();
-    for (const_iterator it = node.begin(); it != node.end(); ++it)
+    for (const auto& element : node)
 #if defined(__GNUC__) && __GNUC__ < 4
       // workaround for GCC 3:
-      rhs.push_back(it->template as<T>());
+      rhs.push_back(element.template as<T>());
 #else
-      rhs.push_back(it->as<T>());
+      rhs.push_back(element.as<T>());
 #endif
     return true;
   }
@@ -294,6 +382,37 @@ struct convert<std::array<T, N>> {
   }
 };
 
+
+// std::valarray
+template <typename T>
+struct convert<std::valarray<T>> {
+  static Node encode(const std::valarray<T>& rhs) {
+    Node node(NodeType::Sequence);
+    for (const auto& element : rhs) {
+      node.push_back(element);
+    }
+    return node;
+  }
+
+  static bool decode(const Node& node, std::valarray<T>& rhs) {
+    if (!node.IsSequence()) {
+      return false;
+    }
+
+    rhs.resize(node.size());
+    for (auto i = 0u; i < node.size(); ++i) {
+#if defined(__GNUC__) && __GNUC__ < 4
+      // workaround for GCC 3:
+      rhs[i] = node[i].template as<T>();
+#else
+      rhs[i] = node[i].as<T>();
+#endif
+    }
+    return true;
+  }
+};
+
+
 // std::pair
 template <typename T, typename U>
 struct convert<std::pair<T, U>> {

include/yaml-cpp/node/detail/impl.h

@@ -9,9 +9,12 @@
 
 #include "yaml-cpp/node/detail/node.h"
 #include "yaml-cpp/node/detail/node_data.h"
+
+#include <algorithm>
 #include <type_traits>
 
 namespace YAML {
+[[noreturn]] void throw_bad_subscript(const YAML::Mark& mark);
 namespace detail {
 template <typename Key, typename Enable = void>
 struct get_idx {
@@ -104,7 +107,11 @@ inline bool node::equals(const T& rhs, shared_memory_holder pMemory) {
 }
 
 inline bool node::equals(const char* rhs, shared_memory_holder pMemory) {
-  return equals<std::string>(rhs, pMemory);
+  std::string lhs;
+  if (convert<std::string>::decode(Node(*this, std::move(pMemory)), lhs)) {
+    return lhs == rhs;
+  }
+  return false;
 }
 
 // indexing
@@ -122,16 +129,14 @@ inline node* node_data::get(const Key& key,
         return pNode;
       return nullptr;
     case NodeType::Scalar:
-      throw BadSubscript(key);
+      throw_bad_subscript(m_mark);
   }
 
-  for (node_map::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
-    if (it->first->equals(key, pMemory)) {
-      return it->second;
-    }
-  }
+  auto it = std::find_if(m_map.begin(), m_map.end(), [&](const kv_pair m) {
+    return m.first->equals(key, pMemory);
+  });
 
-  return nullptr;
+  return it != m_map.end() ? it->second : nullptr;
 }
 
 template <typename Key>
@@ -150,13 +155,15 @@ inline node& node_data::get(const Key& key, shared_memory_holder pMemory) {
       convert_to_map(pMemory);
       break;
     case NodeType::Scalar:
-      throw BadSubscript(key);
+      throw_bad_subscript(m_mark);
   }
 
-  for (node_map::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
-    if (it->first->equals(key, pMemory)) {
-      return *it->second;
-    }
+  auto it = std::find_if(m_map.begin(), m_map.end(), [&](const kv_pair m) {
+    return m.first->equals(key, pMemory);
+  });
+
+  if (it != m_map.end()) {
+    return *it->second;
   }
 
   node& k = convert_to_node(key, pMemory);
@@ -169,7 +176,9 @@ template <typename Key>
 inline bool node_data::remove(const Key& key, shared_memory_holder pMemory) {
   if (m_type == NodeType::Sequence) {
     return remove_idx<Key>::remove(m_sequence, key, m_seqSize);
-  } else if (m_type == NodeType::Map) {
+  }
+
+  if (m_type == NodeType::Map) {
     kv_pairs::iterator it = m_undefinedPairs.begin();
     while (it != m_undefinedPairs.end()) {
       kv_pairs::iterator jt = std::next(it);
@@ -179,17 +188,21 @@ inline bool node_data::remove(const Key& key, shared_memory_holder pMemory) {
       it = jt;
     }
 
-    for (node_map::iterator iter = m_map.begin(); iter != m_map.end(); ++iter) {
-      if (iter->first->equals(key, pMemory)) {
-        m_map.erase(iter);
-        return true;
-      }
+    auto iter = std::find_if(m_map.begin(), m_map.end(), [&](const kv_pair m) {
+      return m.first->equals(key, pMemory);
+    });
+
+    if (iter != m_map.end()) {
+      m_map.erase(iter);
+      return true;
     }
   }
 
   return false;
 }
 
+[[nodiscard]] void throw_bad_insert();
+
 // map
 template <typename Key, typename Value>
 inline void node_data::force_insert(const Key& key, const Value& value,
@@ -203,7 +216,7 @@ inline void node_data::force_insert(const Key& key, const Value& value,
       convert_to_map(pMemory);
       break;
     case NodeType::Scalar:
-      throw BadInsert();
+      throw_bad_insert();
   }
 
   node& k = convert_to_node(key, pMemory);

include/yaml-cpp/node/detail/node.h

@@ -13,12 +13,18 @@
 #include "yaml-cpp/node/ptr.h"
 #include "yaml-cpp/node/type.h"
 #include <set>
+#include <atomic>
 
 namespace YAML {
 namespace detail {
 class node {
+ private:
+  struct less {
+    bool operator ()(const node* l, const node* r) const {return l->m_index < r->m_index;}
+  };
+
  public:
-  node() : m_pRef(new node_ref), m_dependencies{} {}
+  node() : m_pRef(new node_ref), m_dependencies{}, m_index{} {}
   node(const node&) = delete;
   node& operator=(const node&) = delete;
 
@@ -108,6 +114,7 @@ class node {
   void push_back(node& input, shared_memory_holder pMemory) {
     m_pRef->push_back(input, pMemory);
     input.add_dependency(*this);
+    m_index = m_amount.fetch_add(1);
   }
   void insert(node& key, node& value, shared_memory_holder pMemory) {
     m_pRef->insert(key, value, pMemory);
@@ -159,8 +166,10 @@ class node {
 
  private:
   shared_node_ref m_pRef;
-  using nodes = std::set<node*>;
+  using nodes = std::set<node*, less>;
   nodes m_dependencies;
+  size_t m_index;
+  static YAML_CPP_API std::atomic<size_t> m_amount;
 };
 }  // namespace detail
 }  // namespace YAML

include/yaml-cpp/node/detail/node_data.h

@@ -60,8 +60,8 @@ class YAML_CPP_API node_data {
   node_iterator end();
 
   // sequence
-  void push_back(node& node, shared_memory_holder pMemory);
-  void insert(node& key, node& value, shared_memory_holder pMemory);
+  void push_back(node& node, const shared_memory_holder& pMemory);
+  void insert(node& key, node& value, const shared_memory_holder& pMemory);
 
   // indexing
   template <typename Key>
@@ -71,9 +71,9 @@ class YAML_CPP_API node_data {
   template <typename Key>
   bool remove(const Key& key, shared_memory_holder pMemory);
 
-  node* get(node& key, shared_memory_holder pMemory) const;
-  node& get(node& key, shared_memory_holder pMemory);
-  bool remove(node& key, shared_memory_holder pMemory);
+  node* get(node& key, const shared_memory_holder& pMemory) const;
+  node& get(node& key, const shared_memory_holder& pMemory);
+  bool remove(node& key, const shared_memory_holder& pMemory);
 
   // map
   template <typename Key, typename Value>
@@ -91,8 +91,8 @@ class YAML_CPP_API node_data {
   void reset_map();
 
   void insert_map_pair(node& key, node& value);
-  void convert_to_map(shared_memory_holder pMemory);
-  void convert_sequence_to_map(shared_memory_holder pMemory);
+  void convert_to_map(const shared_memory_holder& pMemory);
+  void convert_sequence_to_map(const shared_memory_holder& pMemory);
 
   template <typename T>
   static node& convert_to_node(const T& rhs, shared_memory_holder pMemory);

include/yaml-cpp/node/detail/node_iterator.h

@@ -52,10 +52,7 @@ struct node_iterator_type<const V> {
 };
 
 template <typename V>
-class node_iterator_base
-    : public std::iterator<std::forward_iterator_tag, node_iterator_value<V>,
-                           std::ptrdiff_t, node_iterator_value<V>*,
-                           node_iterator_value<V>> {
+class node_iterator_base {
  private:
   struct enabler {};
 
@@ -68,9 +65,13 @@ class node_iterator_base
   };
 
  public:
+  using iterator_category = std::forward_iterator_tag;
+  using value_type = node_iterator_value<V>;
+  using difference_type = std::ptrdiff_t;
+  using pointer = node_iterator_value<V>*;
+  using reference = node_iterator_value<V>;
   using SeqIter = typename node_iterator_type<V>::seq;
   using MapIter = typename node_iterator_type<V>::map;
-  using value_type = node_iterator_value<V>;
 
   node_iterator_base()
       : m_type(iterator_type::NoneType), m_seqIt(), m_mapIt(), m_mapEnd() {}

include/yaml-cpp/node/impl.h

@@ -16,6 +16,8 @@
 #include <string>
 
 namespace YAML {
+[[noreturn]] extern void throw_invalid_node(const std::string& key);
+[[noreturn]] extern void throw_bad_conversion(const YAML::Mark& mark);
 inline Node::Node()
     : m_isValid(true), m_invalidKey{}, m_pMemory(nullptr), m_pNode(nullptr) {}
 
@@ -42,7 +44,7 @@ inline Node::Node(const detail::iterator_value& rhs)
       m_pMemory(rhs.m_pMemory),
       m_pNode(rhs.m_pNode) {}
 
-inline Node::Node(const Node& rhs) = default;
+inline Node::Node(const Node&) = default;
 
 inline Node::Node(Zombie)
     : m_isValid(false), m_invalidKey{}, m_pMemory{}, m_pNode(nullptr) {}
@@ -57,7 +59,7 @@ inline Node::~Node() = default;
 
 inline void Node::EnsureNodeExists() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   if (!m_pNode) {
     m_pMemory.reset(new detail::memory_holder);
     m_pNode = &m_pMemory->create_node();
@@ -74,14 +76,14 @@ inline bool Node::IsDefined() const {
 
 inline Mark Node::Mark() const {
   if (!m_isValid) {
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   }
   return m_pNode ? m_pNode->mark() : Mark::null_mark();
 }
 
 inline NodeType::value Node::Type() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return m_pNode ? m_pNode->type() : NodeType::Null;
 }
 
@@ -110,6 +112,8 @@ struct as_if<std::string, S> {
   const Node& node;
 
   std::string operator()(const S& fallback) const {
+    if (node.Type() == NodeType::Null)
+      return "null";
     if (node.Type() != NodeType::Scalar)
       return fallback;
     return node.Scalar();
@@ -123,12 +127,12 @@ struct as_if<T, void> {
 
   T operator()() const {
     if (!node.m_pNode)
-      throw TypedBadConversion<T>(node.Mark());
+      throw_bad_conversion(node.Mark()); // <T>
 
     T t;
     if (convert<T>::decode(node, t))
       return t;
-    throw TypedBadConversion<T>(node.Mark());
+    throw_bad_conversion(node.Mark()); // <T>
   }
 };
 
@@ -138,8 +142,10 @@ struct as_if<std::string, void> {
   const Node& node;
 
   std::string operator()() const {
+    if (node.Type() == NodeType::Null)
+      return "null";
     if (node.Type() != NodeType::Scalar)
-      throw TypedBadConversion<std::string>(node.Mark());
+      throw_bad_conversion(node.Mark()); // <std::string>
     return node.Scalar();
   }
 };
@@ -148,7 +154,7 @@ struct as_if<std::string, void> {
 template <typename T>
 inline T Node::as() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return as_if<T, void>(*this)();
 }
 
@@ -161,13 +167,13 @@ inline T Node::as(const S& fallback) const {
 
 inline const std::string& Node::Scalar() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return m_pNode ? m_pNode->scalar() : detail::node_data::empty_scalar();
 }
 
 inline const std::string& Node::Tag() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return m_pNode ? m_pNode->tag() : detail::node_data::empty_scalar();
 }
 
@@ -178,7 +184,7 @@ inline void Node::SetTag(const std::string& tag) {
 
 inline EmitterStyle::value Node::Style() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return m_pNode ? m_pNode->style() : EmitterStyle::Default;
 }
 
@@ -190,7 +196,7 @@ inline void Node::SetStyle(EmitterStyle::value style) {
 // assignment
 inline bool Node::is(const Node& rhs) const {
   if (!m_isValid || !rhs.m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   if (!m_pNode || !rhs.m_pNode)
     return false;
   return m_pNode->is(*rhs.m_pNode);
@@ -211,7 +217,7 @@ inline Node& Node::operator=(const Node& rhs) {
 
 inline void Node::reset(const YAML::Node& rhs) {
   if (!m_isValid || !rhs.m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   m_pMemory = rhs.m_pMemory;
   m_pNode = rhs.m_pNode;
 }
@@ -219,7 +225,7 @@ inline void Node::reset(const YAML::Node& rhs) {
 template <typename T>
 inline void Node::Assign(const T& rhs) {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   AssignData(convert<T>::encode(rhs));
 }
 
@@ -249,7 +255,7 @@ inline void Node::AssignData(const Node& rhs) {
 
 inline void Node::AssignNode(const Node& rhs) {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   rhs.EnsureNodeExists();
 
   if (!m_pNode) {
@@ -266,7 +272,7 @@ inline void Node::AssignNode(const Node& rhs) {
 // size/iterator
 inline std::size_t Node::size() const {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   return m_pNode ? m_pNode->size() : 0;
 }
 
@@ -299,7 +305,7 @@ inline iterator Node::end() {
 template <typename T>
 inline void Node::push_back(const T& rhs) {
   if (!m_isValid)
-    throw InvalidNode(m_invalidKey);
+    throw_invalid_node(m_invalidKey);
   push_back(Node(rhs));
 }
 
@@ -311,51 +317,6 @@ inline void Node::push_back(const Node& rhs) {
   m_pMemory->merge(*rhs.m_pMemory);
 }
 
-// helpers for indexing
-namespace detail {
-template <typename T>
-struct to_value_t {
-  explicit to_value_t(const T& t_) : t(t_) {}
-  const T& t;
-  using return_type = const T &;
-
-  const T& operator()() const { return t; }
-};
-
-template <>
-struct to_value_t<const char*> {
-  explicit to_value_t(const char* t_) : t(t_) {}
-  const char* t;
-  using return_type = std::string;
-
-  const std::string operator()() const { return t; }
-};
-
-template <>
-struct to_value_t<char*> {
-  explicit to_value_t(char* t_) : t(t_) {}
-  const char* t;
-  using return_type = std::string;
-
-  const std::string operator()() const { return t; }
-};
-
-template <std::size_t N>
-struct to_value_t<char[N]> {
-  explicit to_value_t(const char* t_) : t(t_) {}
-  const char* t;
-  using return_type = std::string;
-
-  const std::string operator()() const { return t; }
-};
-
-// converts C-strings to std::strings so they can be copied
-template <typename T>
-inline typename to_value_t<T>::return_type to_value(const T& t) {
-  return to_value_t<T>(t)();
-}
-}  // namespace detail
-
 template<typename Key>
 std::string key_to_string(const Key& key) {
   return streamable_to_string<Key, is_streamable<std::stringstream, Key>::value>().impl(key);
@@ -365,8 +326,8 @@ std::string key_to_string(const Key& key) {
 template <typename Key>
 inline const Node Node::operator[](const Key& key) const {
   EnsureNodeExists();
-  detail::node* value = static_cast<const detail::node&>(*m_pNode).get(
-      detail::to_value(key), m_pMemory);
+  detail::node* value =
+      static_cast<const detail::node&>(*m_pNode).get(key, m_pMemory);
   if (!value) {
     return Node(ZombieNode, key_to_string(key));
   }
@@ -376,14 +337,14 @@ inline const Node Node::operator[](const Key& key) const {
 template <typename Key>
 inline Node Node::operator[](const Key& key) {
   EnsureNodeExists();
-  detail::node& value = m_pNode->get(detail::to_value(key), m_pMemory);
+  detail::node& value = m_pNode->get(key, m_pMemory);
   return Node(value, m_pMemory);
 }
 
 template <typename Key>
 inline bool Node::remove(const Key& key) {
   EnsureNodeExists();
-  return m_pNode->remove(detail::to_value(key), m_pMemory);
+  return m_pNode->remove(key, m_pMemory);
 }
 
 inline const Node Node::operator[](const Node& key) const {
@@ -416,8 +377,7 @@ inline bool Node::remove(const Node& key) {
 template <typename Key, typename Value>
 inline void Node::force_insert(const Key& key, const Value& value) {
   EnsureNodeExists();
-  m_pNode->force_insert(detail::to_value(key), detail::to_value(value),
-                        m_pMemory);
+  m_pNode->force_insert(key, value, m_pMemory);
 }
 
 // free functions

include/yaml-cpp/node/iterator.h

@@ -15,6 +15,9 @@
 #include <utility>
 #include <vector>
 
+// Assert in place so gcc + libc++ combination properly builds
+static_assert(std::is_constructible<YAML::Node, const YAML::Node&>::value, "Node must be copy constructable");
+
 namespace YAML {
 namespace detail {
 struct iterator_value : public Node, std::pair<Node, Node> {

include/yaml-cpp/node/ptr.h

@@ -7,7 +7,6 @@
 #pragma once
 #endif
 
-#include "yaml-cpp/dll.h"
 #include <memory>
 
 namespace YAML {

include/yaml-cpp/stlemitter.h

@@ -16,8 +16,8 @@ namespace YAML {
 template <typename Seq>
 inline Emitter& EmitSeq(Emitter& emitter, const Seq& seq) {
   emitter << BeginSeq;
-  for (typename Seq::const_iterator it = seq.begin(); it != seq.end(); ++it)
-    emitter << *it;
+  for (const auto& v : seq)
+    emitter << v;
   emitter << EndSeq;
   return emitter;
 }
@@ -39,10 +39,9 @@ inline Emitter& operator<<(Emitter& emitter, const std::set<T>& v) {
 
 template <typename K, typename V>
 inline Emitter& operator<<(Emitter& emitter, const std::map<K, V>& m) {
-  typedef typename std::map<K, V> map;
   emitter << BeginMap;
-  for (typename map::const_iterator it = m.begin(); it != m.end(); ++it)
-    emitter << Key << it->first << Value << it->second;
+  for (const auto& v : m)
+    emitter << Key << v.first << Value << v.second;
   emitter << EndMap;
   return emitter;
 }

include/yaml-cpp/traits.h

@@ -107,9 +107,9 @@ struct disable_if : public disable_if_c<Cond::value, T> {};
 
 template <typename S, typename T>
 struct is_streamable {
-  template <typename SS, typename TT>
+  template <typename StreamT, typename ValueT>
   static auto test(int)
-      -> decltype(std::declval<SS&>() << std::declval<TT>(), std::true_type());
+      -> decltype(std::declval<StreamT&>() << std::declval<ValueT>(), std::true_type());
 
   template <typename, typename>
   static auto test(...) -> std::false_type;

src/binary.cpp

@@ -75,11 +75,11 @@ std::vector<unsigned char> DecodeBase64(const std::string &input) {
 
   unsigned value = 0;
   for (std::size_t i = 0, cnt = 0; i < input.size(); i++) {
-    if (std::isspace(input[i])) {
+    if (std::isspace(static_cast<unsigned char>(input[i]))) {
       // skip newlines
       continue;
     }
-    unsigned char d = decoding[static_cast<unsigned>(input[i])];
+    unsigned char d = decoding[static_cast<unsigned char>(input[i])];
     if (d == 255)
       return ret_type();
 
@@ -97,4 +97,4 @@ std::vector<unsigned char> DecodeBase64(const std::string &input) {
   ret.resize(out - &ret[0]);
   return ret;
 }
-}
+}  // namespace YAML

src/contrib/graphbuilder.cpp

@@ -10,8 +10,7 @@ void* BuildGraphOfNextDocument(Parser& parser,
   GraphBuilderAdapter eventHandler(graphBuilder);
   if (parser.HandleNextDocument(eventHandler)) {
     return eventHandler.RootNode();
-  } else {
-    return nullptr;
   }
+  return nullptr;
 }
-}
+}  // namespace YAML

src/contrib/graphbuilderadapter.cpp

@@ -91,4 +91,4 @@ void GraphBuilderAdapter::DispositionNode(void *pNode) {
     m_builder.AppendToSequence(pContainer, pNode);
   }
 }
-}
+}  // namespace YAML

src/contrib/graphbuilderadapter.h

@@ -13,7 +13,6 @@
 
 #include "yaml-cpp/anchor.h"
 #include "yaml-cpp/contrib/anchordict.h"
-#include "yaml-cpp/contrib/graphbuilder.h"
 #include "yaml-cpp/emitterstyle.h"
 #include "yaml-cpp/eventhandler.h"
 

src/convert.cpp

@@ -16,11 +16,7 @@ std::string tolower(const std::string& str) {
 
 template <typename T>
 bool IsEntirely(const std::string& str, T func) {
-  for (char ch : str)
-    if (!func(ch))
-      return false;
-
-  return true;
+  return std::all_of(str.begin(), str.end(), [=](char ch) { return func(ch); });
 }
 
 // IsFlexibleCase

src/depthguard.cpp

@@ -0,0 +1,9 @@
+#include "yaml-cpp/depthguard.h"
+
+namespace YAML {
+
+DeepRecursion::DeepRecursion(int depth, const Mark& mark_,
+                             const std::string& msg_)
+    : ParserException(mark_, msg_), m_depth(depth) {}
+
+}  // namespace YAML

src/directives.cpp

@@ -3,9 +3,9 @@
 namespace YAML {
 Directives::Directives() : version{true, 1, 2}, tags{} {}
 
-const std::string Directives::TranslateTagHandle(
+std::string Directives::TranslateTagHandle(
     const std::string& handle) const {
-  std::map<std::string, std::string>::const_iterator it = tags.find(handle);
+  auto it = tags.find(handle);
   if (it == tags.end()) {
     if (handle == "!!")
       return "tag:yaml.org,2002:";

src/directives.h

@@ -19,7 +19,7 @@ struct Version {
 struct Directives {
   Directives();
 
-  const std::string TranslateTagHandle(const std::string& handle) const;
+  std::string TranslateTagHandle(const std::string& handle) const;
 
   Version version;
   std::map<std::string, std::string> tags;

src/emit.cpp

@@ -1,7 +1,7 @@
 #include "yaml-cpp/node/emit.h"
+#include "nodeevents.h"
 #include "yaml-cpp/emitfromevents.h"
 #include "yaml-cpp/emitter.h"
-#include "nodeevents.h"
 
 namespace YAML {
 Emitter& operator<<(Emitter& out, const Node& node) {

src/emitfromevents.cpp

@@ -59,6 +59,8 @@ void EmitFromEvents::OnSequenceStart(const Mark&, const std::string& tag,
     default:
       break;
   }
+  // Restore the global settings to eliminate the override from node style
+  m_emitter.RestoreGlobalModifiedSettings();
   m_emitter << BeginSeq;
   m_stateStack.push(State::WaitingForSequenceEntry);
 }
@@ -83,6 +85,8 @@ void EmitFromEvents::OnMapStart(const Mark&, const std::string& tag,
     default:
       break;
   }
+  // Restore the global settings to eliminate the override from node style
+  m_emitter.RestoreGlobalModifiedSettings();
   m_emitter << BeginMap;
   m_stateStack.push(State::WaitingForKey);
 }

src/emitter.cpp

@@ -49,6 +49,10 @@ bool Emitter::SetBoolFormat(EMITTER_MANIP value) {
   return ok;
 }
 
+bool Emitter::SetNullFormat(EMITTER_MANIP value) {
+  return m_pState->SetNullFormat(value, FmtScope::Global);
+}
+
 bool Emitter::SetIntBase(EMITTER_MANIP value) {
   return m_pState->SetIntFormat(value, FmtScope::Global);
 }
@@ -86,6 +90,10 @@ bool Emitter::SetDoublePrecision(std::size_t n) {
   return m_pState->SetDoublePrecision(n, FmtScope::Global);
 }
 
+void Emitter::RestoreGlobalModifiedSettings() {
+  m_pState->RestoreGlobalModifiedSettings();
+}
+
 // SetLocalValue
 // . Either start/end a group, or set a modifier locally
 Emitter& Emitter::SetLocalValue(EMITTER_MANIP value) {
@@ -197,6 +205,7 @@ void Emitter::EmitBeginSeq() {
 void Emitter::EmitEndSeq() {
   if (!good())
     return;
+  FlowType::value originalType = m_pState->CurGroupFlowType();
 
   if (m_pState->CurGroupChildCount() == 0)
     m_pState->ForceFlow();
@@ -205,8 +214,12 @@ void Emitter::EmitEndSeq() {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(m_pState->CurIndent());
-    if (m_pState->CurGroupChildCount() == 0)
+    if (originalType == FlowType::Block) {
       m_stream << "[";
+    } else {
+      if (m_pState->CurGroupChildCount() == 0 && !m_pState->HasBegunNode())
+        m_stream << "[";
+    }
     m_stream << "]";
   }
 
@@ -227,6 +240,7 @@ void Emitter::EmitBeginMap() {
 void Emitter::EmitEndMap() {
   if (!good())
     return;
+  FlowType::value originalType = m_pState->CurGroupFlowType();
 
   if (m_pState->CurGroupChildCount() == 0)
     m_pState->ForceFlow();
@@ -235,8 +249,12 @@ void Emitter::EmitEndMap() {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(m_pState->CurIndent());
-    if (m_pState->CurGroupChildCount() == 0)
+    if (originalType == FlowType::Block) {
       m_stream << "{";
+    } else {
+      if (m_pState->CurGroupChildCount() == 0 && !m_pState->HasBegunNode())
+        m_stream << "{";
+    }
     m_stream << "}";
   }
 
@@ -486,6 +504,9 @@ void Emitter::FlowMapPrepareSimpleKeyValue(EmitterNodeType::value child) {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(lastIndent);
+    if (m_pState->HasAlias()) {
+      m_stream << " ";
+    }
     m_stream << ":";
   }
 
@@ -512,7 +533,8 @@ void Emitter::BlockMapPrepareNode(EmitterNodeType::value child) {
     if (m_pState->GetMapKeyFormat() == LongKey)
       m_pState->SetLongKey();
     if (child == EmitterNodeType::BlockSeq ||
-        child == EmitterNodeType::BlockMap)
+        child == EmitterNodeType::BlockMap ||
+        child == EmitterNodeType::Property)
       m_pState->SetLongKey();
 
     if (m_pState->CurGroupLongKey())
@@ -556,6 +578,8 @@ void Emitter::BlockMapPrepareLongKey(EmitterNodeType::value child) {
       break;
     case EmitterNodeType::BlockSeq:
     case EmitterNodeType::BlockMap:
+      if (m_pState->HasBegunContent())
+        m_stream << "\n";
       break;
   }
 }
@@ -579,8 +603,12 @@ void Emitter::BlockMapPrepareLongKeyValue(EmitterNodeType::value child) {
     case EmitterNodeType::Scalar:
     case EmitterNodeType::FlowSeq:
     case EmitterNodeType::FlowMap:
+      SpaceOrIndentTo(true, curIndent + 1);
+      break;
     case EmitterNodeType::BlockSeq:
     case EmitterNodeType::BlockMap:
+      if (m_pState->HasBegunContent())
+        m_stream << "\n";
       SpaceOrIndentTo(true, curIndent + 1);
       break;
   }
@@ -619,6 +647,9 @@ void Emitter::BlockMapPrepareSimpleKeyValue(EmitterNodeType::value child) {
   const std::size_t nextIndent = curIndent + m_pState->CurGroupIndent();
 
   if (!m_pState->HasBegunNode()) {
+    if (m_pState->HasAlias()) {
+      m_stream << " ";
+    }
     m_stream << ":";
   }
 
@@ -672,16 +703,29 @@ void Emitter::StartedScalar() { m_pState->StartedScalar(); }
 // *******************************************************************************************
 // overloads of Write
 
+StringEscaping::value GetStringEscapingStyle(const EMITTER_MANIP emitterManip) {
+  switch (emitterManip) {
+    case EscapeNonAscii:
+      return StringEscaping::NonAscii;
+    case EscapeAsJson:
+      return StringEscaping::JSON;
+    default:
+      return StringEscaping::None;
+      break;
+  }
+}
+
 Emitter& Emitter::Write(const std::string& str) {
   if (!good())
     return *this;
 
-  const bool escapeNonAscii = m_pState->GetOutputCharset() == EscapeNonAscii;
+  StringEscaping::value stringEscaping = GetStringEscapingStyle(m_pState->GetOutputCharset());
+
   const StringFormat::value strFormat =
       Utils::ComputeStringFormat(str, m_pState->GetStringFormat(),
-                                 m_pState->CurGroupFlowType(), escapeNonAscii);
+                                 m_pState->CurGroupFlowType(), stringEscaping == StringEscaping::NonAscii);
 
-  if (strFormat == StringFormat::Literal)
+  if (strFormat == StringFormat::Literal || str.size() > 1024)
     m_pState->SetMapKeyFormat(YAML::LongKey, FmtScope::Local);
 
   PrepareNode(EmitterNodeType::Scalar);
@@ -694,7 +738,7 @@ Emitter& Emitter::Write(const std::string& str) {
       Utils::WriteSingleQuotedString(m_stream, str);
       break;
     case StringFormat::DoubleQuoted:
-      Utils::WriteDoubleQuotedString(m_stream, str, escapeNonAscii);
+      Utils::WriteDoubleQuotedString(m_stream, str, stringEscaping);
       break;
     case StringFormat::Literal:
       Utils::WriteLiteralString(m_stream, str,
@@ -764,6 +808,21 @@ const char* Emitter::ComputeFullBoolName(bool b) const {
                          // these answers
 }
 
+const char* Emitter::ComputeNullName() const {
+  switch (m_pState->GetNullFormat()) {
+    case LowerNull:
+      return "null";
+    case UpperNull:
+      return "NULL";
+    case CamelNull:
+      return "Null";
+    case TildeNull:
+      // fallthrough
+    default:
+      return "~";
+  }
+}
+
 Emitter& Emitter::Write(bool b) {
   if (!good())
     return *this;
@@ -785,8 +844,10 @@ Emitter& Emitter::Write(char ch) {
   if (!good())
     return *this;
 
+
+
   PrepareNode(EmitterNodeType::Scalar);
-  Utils::WriteChar(m_stream, ch);
+  Utils::WriteChar(m_stream, ch, GetStringEscapingStyle(m_pState->GetOutputCharset()));
   StartedScalar();
 
   return *this;
@@ -810,6 +871,8 @@ Emitter& Emitter::Write(const _Alias& alias) {
 
   StartedScalar();
 
+  m_pState->SetAlias();
+
   return *this;
 }
 
@@ -887,7 +950,7 @@ Emitter& Emitter::Write(const _Null& /*null*/) {
 
   PrepareNode(EmitterNodeType::Scalar);
 
-  m_stream << "~";
+  m_stream << ComputeNullName();
 
   StartedScalar();
 

src/emitterstate.cpp

@@ -13,6 +13,7 @@ EmitterState::EmitterState()
       m_boolFmt(TrueFalseBool),
       m_boolLengthFmt(LongBool),
       m_boolCaseFmt(LowerCase),
+      m_nullFmt(TildeNull),
       m_intFmt(Dec),
       m_indent(2),
       m_preCommentIndent(2),
@@ -28,6 +29,7 @@ EmitterState::EmitterState()
       m_groups{},
       m_curIndent(0),
       m_hasAnchor(false),
+      m_hasAlias(false),
       m_hasTag(false),
       m_hasNonContent(false),
       m_docCount(0) {}
@@ -43,6 +45,7 @@ void EmitterState::SetLocalValue(EMITTER_MANIP value) {
   SetBoolFormat(value, FmtScope::Local);
   SetBoolCaseFormat(value, FmtScope::Local);
   SetBoolLengthFormat(value, FmtScope::Local);
+  SetNullFormat(value, FmtScope::Local);
   SetIntFormat(value, FmtScope::Local);
   SetFlowType(GroupType::Seq, value, FmtScope::Local);
   SetFlowType(GroupType::Map, value, FmtScope::Local);
@@ -51,6 +54,8 @@ void EmitterState::SetLocalValue(EMITTER_MANIP value) {
 
 void EmitterState::SetAnchor() { m_hasAnchor = true; }
 
+void EmitterState::SetAlias() { m_hasAlias = true; }
+
 void EmitterState::SetTag() { m_hasTag = true; }
 
 void EmitterState::SetNonContent() { m_hasNonContent = true; }
@@ -85,6 +90,7 @@ void EmitterState::StartedNode() {
   }
 
   m_hasAnchor = false;
+  m_hasAlias = false;
   m_hasTag = false;
   m_hasNonContent = false;
 }
@@ -94,15 +100,13 @@ EmitterNodeType::value EmitterState::NextGroupType(
   if (type == GroupType::Seq) {
     if (GetFlowType(type) == Block)
       return EmitterNodeType::BlockSeq;
-    else
-      return EmitterNodeType::FlowSeq;
-  } else {
-    if (GetFlowType(type) == Block)
-      return EmitterNodeType::BlockMap;
-    else
-      return EmitterNodeType::FlowMap;
+    return EmitterNodeType::FlowSeq;
   }
 
+  if (GetFlowType(type) == Block)
+    return EmitterNodeType::BlockMap;
+  return EmitterNodeType::FlowMap;
+
   // can't happen
   assert(false);
   return EmitterNodeType::NoType;
@@ -156,9 +160,15 @@ void EmitterState::EndedGroup(GroupType::value type) {
   if (m_groups.empty()) {
     if (type == GroupType::Seq) {
       return SetError(ErrorMsg::UNEXPECTED_END_SEQ);
-    } else {
-      return SetError(ErrorMsg::UNEXPECTED_END_MAP);
     }
+    return SetError(ErrorMsg::UNEXPECTED_END_MAP);
+  }
+
+  if (m_hasTag) {
+    SetError(ErrorMsg::INVALID_TAG);
+  }
+  if (m_hasAnchor) {
+    SetError(ErrorMsg::INVALID_ANCHOR);
   }
 
   // get rid of the current group
@@ -180,6 +190,9 @@ void EmitterState::EndedGroup(GroupType::value type) {
   m_globalModifiedSettings.restore();
 
   ClearModifiedSettings();
+  m_hasAnchor = false;
+  m_hasTag = false;
+  m_hasNonContent = false;
 }
 
 EmitterNodeType::value EmitterState::CurGroupNodeType() const {
@@ -220,11 +233,16 @@ std::size_t EmitterState::LastIndent() const {
 
 void EmitterState::ClearModifiedSettings() { m_modifiedSettings.clear(); }
 
+void EmitterState::RestoreGlobalModifiedSettings() {
+  m_globalModifiedSettings.restore();
+}
+
 bool EmitterState::SetOutputCharset(EMITTER_MANIP value,
                                     FmtScope::value scope) {
   switch (value) {
     case EmitNonAscii:
     case EscapeNonAscii:
+    case EscapeAsJson:
       _Set(m_charset, value, scope);
       return true;
     default:
@@ -282,6 +300,19 @@ bool EmitterState::SetBoolCaseFormat(EMITTER_MANIP value,
   }
 }
 
+bool EmitterState::SetNullFormat(EMITTER_MANIP value, FmtScope::value scope) {
+  switch (value) {
+    case LowerNull:
+    case UpperNull:
+    case CamelNull:
+    case TildeNull:
+      _Set(m_nullFmt, value, scope);
+      return true;
+    default:
+      return false;
+  }
+}
+
 bool EmitterState::SetIntFormat(EMITTER_MANIP value, FmtScope::value scope) {
   switch (value) {
     case Dec:

src/emitterstate.h

@@ -43,6 +43,7 @@ class EmitterState {
 
   // node handling
   void SetAnchor();
+  void SetAlias();
   void SetTag();
   void SetNonContent();
   void SetLongKey();
@@ -65,6 +66,7 @@ class EmitterState {
   std::size_t LastIndent() const;
   std::size_t CurIndent() const { return m_curIndent; }
   bool HasAnchor() const { return m_hasAnchor; }
+  bool HasAlias() const { return m_hasAlias; }
   bool HasTag() const { return m_hasTag; }
   bool HasBegunNode() const {
     return m_hasAnchor || m_hasTag || m_hasNonContent;
@@ -72,6 +74,7 @@ class EmitterState {
   bool HasBegunContent() const { return m_hasAnchor || m_hasTag; }
 
   void ClearModifiedSettings();
+  void RestoreGlobalModifiedSettings();
 
   // formatters
   void SetLocalValue(EMITTER_MANIP value);
@@ -91,6 +94,9 @@ class EmitterState {
   bool SetBoolCaseFormat(EMITTER_MANIP value, FmtScope::value scope);
   EMITTER_MANIP GetBoolCaseFormat() const { return m_boolCaseFmt.get(); }
 
+  bool SetNullFormat(EMITTER_MANIP value, FmtScope::value scope);
+  EMITTER_MANIP GetNullFormat() const { return m_nullFmt.get(); }
+
   bool SetIntFormat(EMITTER_MANIP value, FmtScope::value scope);
   EMITTER_MANIP GetIntFormat() const { return m_intFmt.get(); }
 
@@ -131,6 +137,7 @@ class EmitterState {
   Setting<EMITTER_MANIP> m_boolFmt;
   Setting<EMITTER_MANIP> m_boolLengthFmt;
   Setting<EMITTER_MANIP> m_boolCaseFmt;
+  Setting<EMITTER_MANIP> m_nullFmt;
   Setting<EMITTER_MANIP> m_intFmt;
   Setting<std::size_t> m_indent;
   Setting<std::size_t> m_preCommentIndent, m_postCommentIndent;
@@ -182,6 +189,7 @@ class EmitterState {
   std::vector<std::unique_ptr<Group>> m_groups;
   std::size_t m_curIndent;
   bool m_hasAnchor;
+  bool m_hasAlias;
   bool m_hasTag;
   bool m_hasNonContent;
   std::size_t m_docCount;

src/emitterutils.cpp

@@ -1,3 +1,4 @@
+#include <algorithm>
 #include <iomanip>
 #include <sstream>
 
@@ -175,11 +176,11 @@ bool IsValidPlainScalar(const std::string& str, FlowType::value flowType,
   static const RegEx& disallowed_flow =
       Exp::EndScalarInFlow() | (Exp::BlankOrBreak() + Exp::Comment()) |
       Exp::NotPrintable() | Exp::Utf8_ByteOrderMark() | Exp::Break() |
-      Exp::Tab();
+      Exp::Tab() | Exp::Ampersand();
   static const RegEx& disallowed_block =
       Exp::EndScalar() | (Exp::BlankOrBreak() + Exp::Comment()) |
       Exp::NotPrintable() | Exp::Utf8_ByteOrderMark() | Exp::Break() |
-      Exp::Tab();
+      Exp::Tab() | Exp::Ampersand();
   const RegEx& disallowed =
       flowType == FlowType::Flow ? disallowed_flow : disallowed_block;
 
@@ -199,15 +200,10 @@ bool IsValidPlainScalar(const std::string& str, FlowType::value flowType,
 
 bool IsValidSingleQuotedScalar(const std::string& str, bool escapeNonAscii) {
   // TODO: check for non-printable characters?
-  for (char ch : str) {
-    if (escapeNonAscii && (0x80 <= static_cast<unsigned char>(ch))) {
-      return false;
-    }
-    if (ch == '\n') {
-      return false;
-    }
-  }
-  return true;
+  return std::none_of(str.begin(), str.end(), [=](char ch) {
+    return (escapeNonAscii && (0x80 <= static_cast<unsigned char>(ch))) ||
+           (ch == '\n');
+  });
 }
 
 bool IsValidLiteralScalar(const std::string& str, FlowType::value flowType,
@@ -217,28 +213,39 @@ bool IsValidLiteralScalar(const std::string& str, FlowType::value flowType,
   }
 
   // TODO: check for non-printable characters?
-  for (char ch : str) {
-    if (escapeNonAscii && (0x80 <= static_cast<unsigned char>(ch))) {
-      return false;
-    }
-  }
-  return true;
+  return std::none_of(str.begin(), str.end(), [=](char ch) {
+    return (escapeNonAscii && (0x80 <= static_cast<unsigned char>(ch)));
+  });
 }
 
-void WriteDoubleQuoteEscapeSequence(ostream_wrapper& out, int codePoint) {
+std::pair<uint16_t, uint16_t> EncodeUTF16SurrogatePair(int codePoint) {
+  const uint32_t leadOffset = 0xD800 - (0x10000 >> 10);
+
+  return {
+    leadOffset | (codePoint >> 10),
+    0xDC00 | (codePoint & 0x3FF),
+  };
+}
+
+void WriteDoubleQuoteEscapeSequence(ostream_wrapper& out, int codePoint, StringEscaping::value stringEscapingStyle) {
   static const char hexDigits[] = "0123456789abcdef";
 
   out << "\\";
   int digits = 8;
-  if (codePoint < 0xFF) {
+  if (codePoint < 0xFF && stringEscapingStyle != StringEscaping::JSON) {
     out << "x";
     digits = 2;
   } else if (codePoint < 0xFFFF) {
     out << "u";
     digits = 4;
-  } else {
+  } else if (stringEscapingStyle != StringEscaping::JSON) {
     out << "U";
     digits = 8;
+  } else {
+    auto surrogatePair = EncodeUTF16SurrogatePair(codePoint);
+    WriteDoubleQuoteEscapeSequence(out, surrogatePair.first, stringEscapingStyle);
+    WriteDoubleQuoteEscapeSequence(out, surrogatePair.second, stringEscapingStyle);
+    return;
   }
 
   // Write digits into the escape sequence
@@ -310,7 +317,7 @@ bool WriteSingleQuotedString(ostream_wrapper& out, const std::string& str) {
 }
 
 bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
-                             bool escapeNonAscii) {
+                             StringEscaping::value stringEscaping) {
   out << "\"";
   int codePoint;
   for (std::string::const_iterator i = str.begin();
@@ -334,16 +341,19 @@ bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
       case '\b':
         out << "\\b";
         break;
+      case '\f':
+        out << "\\f";
+        break;
       default:
         if (codePoint < 0x20 ||
             (codePoint >= 0x80 &&
              codePoint <= 0xA0)) {  // Control characters and non-breaking space
-          WriteDoubleQuoteEscapeSequence(out, codePoint);
+          WriteDoubleQuoteEscapeSequence(out, codePoint, stringEscaping);
         } else if (codePoint == 0xFEFF) {  // Byte order marks (ZWNS) should be
                                            // escaped (YAML 1.2, sec. 5.2)
-          WriteDoubleQuoteEscapeSequence(out, codePoint);
-        } else if (escapeNonAscii && codePoint > 0x7E) {
-          WriteDoubleQuoteEscapeSequence(out, codePoint);
+          WriteDoubleQuoteEscapeSequence(out, codePoint, stringEscaping);
+        } else if (stringEscaping == StringEscaping::NonAscii && codePoint > 0x7E) {
+          WriteDoubleQuoteEscapeSequence(out, codePoint, stringEscaping);
         } else {
           WriteCodePoint(out, codePoint);
         }
@@ -356,37 +366,41 @@ bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
 bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
                         std::size_t indent) {
   out << "|\n";
-  out << IndentTo(indent);
   int codePoint;
   for (std::string::const_iterator i = str.begin();
        GetNextCodePointAndAdvance(codePoint, i, str.end());) {
     if (codePoint == '\n') {
-      out << "\n" << IndentTo(indent);
+      out << "\n";
     } else {
+      out<< IndentTo(indent);
       WriteCodePoint(out, codePoint);
     }
   }
   return true;
 }
 
-bool WriteChar(ostream_wrapper& out, char ch) {
+bool WriteChar(ostream_wrapper& out, char ch, StringEscaping::value stringEscapingStyle) {
   if (('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z')) {
     out << ch;
   } else if (ch == '\"') {
-    out << "\"\\\"\"";
+    out << R"("\"")";
   } else if (ch == '\t') {
-    out << "\"\\t\"";
+    out << R"("\t")";
   } else if (ch == '\n') {
-    out << "\"\\n\"";
+    out << R"("\n")";
   } else if (ch == '\b') {
-    out << "\"\\b\"";
+    out << R"("\b")";
+  } else if (ch == '\r') {
+    out << R"("\r")";
+  } else if (ch == '\f') {
+    out << R"("\f")";
   } else if (ch == '\\') {
-    out << "\"\\\\\"";
+    out << R"("\\")";
   } else if (0x20 <= ch && ch <= 0x7e) {
     out << "\"" << ch << "\"";
   } else {
     out << "\"";
-    WriteDoubleQuoteEscapeSequence(out, ch);
+    WriteDoubleQuoteEscapeSequence(out, ch, stringEscapingStyle);
     out << "\"";
   }
   return true;
@@ -476,7 +490,7 @@ bool WriteTagWithPrefix(ostream_wrapper& out, const std::string& prefix,
 
 bool WriteBinary(ostream_wrapper& out, const Binary& binary) {
   WriteDoubleQuotedString(out, EncodeBase64(binary.data(), binary.size()),
-                          false);
+                          StringEscaping::None);
   return true;
 }
 }  // namespace Utils

src/emitterutils.h

@@ -24,6 +24,10 @@ struct StringFormat {
   enum value { Plain, SingleQuoted, DoubleQuoted, Literal };
 };
 
+struct StringEscaping {
+  enum value { None, NonAscii, JSON };
+};
+
 namespace Utils {
 StringFormat::value ComputeStringFormat(const std::string& str,
                                         EMITTER_MANIP strFormat,
@@ -32,10 +36,11 @@ StringFormat::value ComputeStringFormat(const std::string& str,
 
 bool WriteSingleQuotedString(ostream_wrapper& out, const std::string& str);
 bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
-                             bool escapeNonAscii);
+                             StringEscaping::value stringEscaping);
 bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
                         std::size_t indent);
-bool WriteChar(ostream_wrapper& out, char ch);
+bool WriteChar(ostream_wrapper& out, char ch,
+               StringEscaping::value stringEscapingStyle);
 bool WriteComment(ostream_wrapper& out, const std::string& str,
                   std::size_t postCommentIndent);
 bool WriteAlias(ostream_wrapper& out, const std::string& str);

src/exceptions.cpp

@@ -17,4 +17,24 @@ BadPushback::~BadPushback() YAML_CPP_NOEXCEPT = default;
 BadInsert::~BadInsert() YAML_CPP_NOEXCEPT = default;
 EmitterException::~EmitterException() YAML_CPP_NOEXCEPT = default;
 BadFile::~BadFile() YAML_CPP_NOEXCEPT = default;
+
+[[noreturn]] void throw_bad_subscript(const YAML::Mark& mark)
+{
+	throw BadSubscript(mark, std::string{});
 }
+
+[[noreturn]] void throw_invalid_node(const std::string& key)
+{
+	throw InvalidNode(key);
+}
+
+[[noreturn]] void throw_bad_conversion(const YAML::Mark& mark)
+{
+	throw BadConversion(mark);
+}
+
+[[noreturn]] void throw_bad_insert()
+{
+	throw BadInsert();
+}
+}  // namespace YAML

src/exp.cpp

@@ -54,14 +54,16 @@ std::string Escape(Stream& in, int codeLength) {
   // now break it up into chars
   if (value <= 0x7F)
     return Str(value);
-  else if (value <= 0x7FF)
+
+  if (value <= 0x7FF)
     return Str(0xC0 + (value >> 6)) + Str(0x80 + (value & 0x3F));
-  else if (value <= 0xFFFF)
+
+  if (value <= 0xFFFF)
     return Str(0xE0 + (value >> 12)) + Str(0x80 + ((value >> 6) & 0x3F)) +
            Str(0x80 + (value & 0x3F));
-  else
-    return Str(0xF0 + (value >> 18)) + Str(0x80 + ((value >> 12) & 0x3F)) +
-           Str(0x80 + ((value >> 6) & 0x3F)) + Str(0x80 + (value & 0x3F));
+
+  return Str(0xF0 + (value >> 18)) + Str(0x80 + ((value >> 12) & 0x3F)) +
+         Str(0x80 + ((value >> 6) & 0x3F)) + Str(0x80 + (value & 0x3F));
 }
 
 // Escape
@@ -103,7 +105,7 @@ std::string Escape(Stream& in) {
     case 'e':
       return "\x1B";
     case ' ':
-      return "\x20";
+      return R"( )";
     case '\"':
       return "\"";
     case '\'':

src/exp.h

@@ -37,7 +37,7 @@ inline const RegEx& Blank() {
   return e;
 }
 inline const RegEx& Break() {
-  static const RegEx e = RegEx('\n') | RegEx("\r\n");
+  static const RegEx e = RegEx('\n') | RegEx("\r\n") | RegEx('\r');
   return e;
 }
 inline const RegEx& BlankOrBreak() {
@@ -110,13 +110,17 @@ inline const RegEx& Value() {
   return e;
 }
 inline const RegEx& ValueInFlow() {
-  static const RegEx e = RegEx(':') + (BlankOrBreak() | RegEx(",}", REGEX_OR));
+  static const RegEx e = RegEx(':') + (BlankOrBreak() | RegEx(",]}", REGEX_OR));
   return e;
 }
 inline const RegEx& ValueInJSONFlow() {
   static const RegEx e = RegEx(':');
   return e;
 }
+inline const RegEx& Ampersand() {
+  static const RegEx e = RegEx('&');
+  return e;
+}
 inline const RegEx Comment() {
   static const RegEx e = RegEx('#');
   return e;
@@ -155,7 +159,7 @@ inline const RegEx& PlainScalar() {
 inline const RegEx& PlainScalarInFlow() {
   static const RegEx e =
       !(BlankOrBreak() | RegEx("?,[]{}#&*!|>\'\"%@`", REGEX_OR) |
-        (RegEx("-:", REGEX_OR) + Blank()));
+        (RegEx("-:", REGEX_OR) + (Blank() | RegEx())));
   return e;
 }
 inline const RegEx& EndScalar() {

src/memory.cpp

@@ -22,5 +22,5 @@ node& memory::create_node() {
 void memory::merge(const memory& rhs) {
   m_nodes.insert(rhs.m_nodes.begin(), rhs.m_nodes.end());
 }
-}
-}
+}  // namespace detail
+}  // namespace YAML

src/node.cpp

@@ -9,4 +9,4 @@ Node Clone(const Node& node) {
   events.Emit(builder);
   return builder.Root();
 }
-}
+}  // namespace YAML

src/node_data.cpp

@@ -1,3 +1,4 @@
+#include <algorithm>
 #include <cassert>
 #include <iterator>
 #include <sstream>
@@ -12,6 +13,7 @@
 
 namespace YAML {
 namespace detail {
+YAML_CPP_API std::atomic<size_t> node::m_amount{0};
 
 const std::string& node_data::empty_scalar() {
   static const std::string svalue;
@@ -108,9 +110,9 @@ void node_data::compute_seq_size() const {
 }
 
 void node_data::compute_map_size() const {
-  kv_pairs::iterator it = m_undefinedPairs.begin();
+  auto it = m_undefinedPairs.begin();
   while (it != m_undefinedPairs.end()) {
-    kv_pairs::iterator jt = std::next(it);
+    auto jt = std::next(it);
     if (it->first->is_defined() && it->second->is_defined())
       m_undefinedPairs.erase(it);
     it = jt;
@@ -119,7 +121,7 @@ void node_data::compute_map_size() const {
 
 const_node_iterator node_data::begin() const {
   if (!m_isDefined)
-    return const_node_iterator();
+    return {};
 
   switch (m_type) {
     case NodeType::Sequence:
@@ -127,13 +129,13 @@ const_node_iterator node_data::begin() const {
     case NodeType::Map:
       return const_node_iterator(m_map.begin(), m_map.end());
     default:
-      return const_node_iterator();
+      return {};
   }
 }
 
 node_iterator node_data::begin() {
   if (!m_isDefined)
-    return node_iterator();
+    return {};
 
   switch (m_type) {
     case NodeType::Sequence:
@@ -141,13 +143,13 @@ node_iterator node_data::begin() {
     case NodeType::Map:
       return node_iterator(m_map.begin(), m_map.end());
     default:
-      return node_iterator();
+      return {};
   }
 }
 
 const_node_iterator node_data::end() const {
   if (!m_isDefined)
-    return const_node_iterator();
+    return {};
 
   switch (m_type) {
     case NodeType::Sequence:
@@ -155,13 +157,13 @@ const_node_iterator node_data::end() const {
     case NodeType::Map:
       return const_node_iterator(m_map.end(), m_map.end());
     default:
-      return const_node_iterator();
+      return {};
   }
 }
 
 node_iterator node_data::end() {
   if (!m_isDefined)
-    return node_iterator();
+    return {};
 
   switch (m_type) {
     case NodeType::Sequence:
@@ -169,12 +171,13 @@ node_iterator node_data::end() {
     case NodeType::Map:
       return node_iterator(m_map.end(), m_map.end());
     default:
-      return node_iterator();
+      return {};
   }
 }
 
 // sequence
-void node_data::push_back(node& node, shared_memory_holder /* pMemory */) {
+void node_data::push_back(node& node,
+                          const shared_memory_holder& /* pMemory */) {
   if (m_type == NodeType::Undefined || m_type == NodeType::Null) {
     m_type = NodeType::Sequence;
     reset_sequence();
@@ -186,7 +189,8 @@ void node_data::push_back(node& node, shared_memory_holder /* pMemory */) {
   m_sequence.push_back(&node);
 }
 
-void node_data::insert(node& key, node& value, shared_memory_holder pMemory) {
+void node_data::insert(node& key, node& value,
+                       const shared_memory_holder& pMemory) {
   switch (m_type) {
     case NodeType::Map:
       break;
@@ -196,27 +200,28 @@ void node_data::insert(node& key, node& value, shared_memory_holder pMemory) {
       convert_to_map(pMemory);
       break;
     case NodeType::Scalar:
-      throw BadSubscript(key);
+      throw BadSubscript(m_mark, key);
   }
 
   insert_map_pair(key, value);
 }
 
 // indexing
-node* node_data::get(node& key, shared_memory_holder /* pMemory */) const {
+node* node_data::get(node& key,
+                     const shared_memory_holder& /* pMemory */) const {
   if (m_type != NodeType::Map) {
     return nullptr;
   }
 
-  for (node_map::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
-    if (it->first->is(key))
-      return it->second;
+  for (const auto& it : m_map) {
+    if (it.first->is(key))
+      return it.second;
   }
 
   return nullptr;
 }
 
-node& node_data::get(node& key, shared_memory_holder pMemory) {
+node& node_data::get(node& key, const shared_memory_holder& pMemory) {
   switch (m_type) {
     case NodeType::Map:
       break;
@@ -226,12 +231,12 @@ node& node_data::get(node& key, shared_memory_holder pMemory) {
       convert_to_map(pMemory);
       break;
     case NodeType::Scalar:
-      throw BadSubscript(key);
+      throw BadSubscript(m_mark, key);
   }
 
-  for (node_map::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
-    if (it->first->is(key))
-      return *it->second;
+  for (const auto& it : m_map) {
+    if (it.first->is(key))
+      return *it.second;
   }
 
   node& value = pMemory->create_node();
@@ -239,23 +244,26 @@ node& node_data::get(node& key, shared_memory_holder pMemory) {
   return value;
 }
 
-bool node_data::remove(node& key, shared_memory_holder /* pMemory */) {
+bool node_data::remove(node& key, const shared_memory_holder& /* pMemory */) {
   if (m_type != NodeType::Map)
     return false;
 
-  for (kv_pairs::iterator it = m_undefinedPairs.begin();
-       it != m_undefinedPairs.end();) {
-    kv_pairs::iterator jt = std::next(it);
+  for (auto it = m_undefinedPairs.begin(); it != m_undefinedPairs.end();) {
+    auto jt = std::next(it);
     if (it->first->is(key))
       m_undefinedPairs.erase(it);
     it = jt;
   }
 
-  for (node_map::iterator it = m_map.begin(); it != m_map.end(); ++it) {
-    if (it->first->is(key)) {
-      m_map.erase(it);
-      return true;
-    }
+  auto it =
+      std::find_if(m_map.begin(), m_map.end(),
+                   [&](std::pair<YAML::detail::node*, YAML::detail::node*> j) {
+                     return (j.first->is(key));
+                   });
+
+  if (it != m_map.end()) {
+    m_map.erase(it);
+    return true;
   }
 
   return false;
@@ -278,7 +286,7 @@ void node_data::insert_map_pair(node& key, node& value) {
     m_undefinedPairs.emplace_back(&key, &value);
 }
 
-void node_data::convert_to_map(shared_memory_holder pMemory) {
+void node_data::convert_to_map(const shared_memory_holder& pMemory) {
   switch (m_type) {
     case NodeType::Undefined:
     case NodeType::Null:
@@ -296,7 +304,7 @@ void node_data::convert_to_map(shared_memory_holder pMemory) {
   }
 }
 
-void node_data::convert_sequence_to_map(shared_memory_holder pMemory) {
+void node_data::convert_sequence_to_map(const shared_memory_holder& pMemory) {
   assert(m_type == NodeType::Sequence);
 
   reset_map();

src/nodebuilder.cpp

@@ -92,7 +92,7 @@ void NodeBuilder::Push(detail::node& node) {
 
   m_stack.push_back(&node);
   if (needsKey)
-    m_keys.push_back(PushedKey(&node, false));
+    m_keys.emplace_back(&node, false);
 }
 
 void NodeBuilder::Pop() {

src/nodeevents.cpp

@@ -13,7 +13,7 @@ void NodeEvents::AliasManager::RegisterReference(const detail::node& node) {
 
 anchor_t NodeEvents::AliasManager::LookupAnchor(
     const detail::node& node) const {
-  AnchorByIdentity::const_iterator it = m_anchorByIdentity.find(node.ref());
+  auto it = m_anchorByIdentity.find(node.ref());
   if (it == m_anchorByIdentity.end())
     return 0;
   return it->second;
@@ -32,13 +32,12 @@ void NodeEvents::Setup(const detail::node& node) {
     return;
 
   if (node.type() == NodeType::Sequence) {
-    for (detail::const_node_iterator it = node.begin(); it != node.end(); ++it)
-      Setup(**it);
+    for (auto element : node)
+      Setup(*element);
   } else if (node.type() == NodeType::Map) {
-    for (detail::const_node_iterator it = node.begin(); it != node.end();
-         ++it) {
-      Setup(*it->first);
-      Setup(*it->second);
+    for (auto element : node) {
+      Setup(*element.first);
+      Setup(*element.second);
     }
   }
 }
@@ -77,17 +76,15 @@ void NodeEvents::Emit(const detail::node& node, EventHandler& handler,
       break;
     case NodeType::Sequence:
       handler.OnSequenceStart(Mark(), node.tag(), anchor, node.style());
-      for (detail::const_node_iterator it = node.begin(); it != node.end();
-           ++it)
-        Emit(**it, handler, am);
+      for (auto element : node)
+        Emit(*element, handler, am);
       handler.OnSequenceEnd();
       break;
     case NodeType::Map:
       handler.OnMapStart(Mark(), node.tag(), anchor, node.style());
-      for (detail::const_node_iterator it = node.begin(); it != node.end();
-           ++it) {
-        Emit(*it->first, handler, am);
-        Emit(*it->second, handler, am);
+      for (auto element : node) {
+        Emit(*element.first, handler, am);
+        Emit(*element.second, handler, am);
       }
       handler.OnMapEnd();
       break;
@@ -95,7 +92,7 @@ void NodeEvents::Emit(const detail::node& node, EventHandler& handler,
 }
 
 bool NodeEvents::IsAliased(const detail::node& node) const {
-  RefCount::const_iterator it = m_refCount.find(node.ref());
+  auto it = m_refCount.find(node.ref());
   return it != m_refCount.end() && it->second > 1;
 }
 }  // namespace YAML

src/null.cpp

@@ -7,4 +7,4 @@ bool IsNullString(const std::string& str) {
   return str.empty() || str == "~" || str == "null" || str == "Null" ||
          str == "NULL";
 }
-}
+}  // namespace YAML

src/parse.cpp

@@ -3,10 +3,10 @@
 #include <fstream>
 #include <sstream>
 
-#include "yaml-cpp/node/node.h"
-#include "yaml-cpp/node/impl.h"
-#include "yaml-cpp/parser.h"
 #include "nodebuilder.h"
+#include "yaml-cpp/node/impl.h"
+#include "yaml-cpp/node/node.h"
+#include "yaml-cpp/parser.h"
 
 namespace YAML {
 Node Load(const std::string& input) {
@@ -30,9 +30,9 @@ Node Load(std::istream& input) {
 }
 
 Node LoadFile(const std::string& filename) {
-  std::ifstream fin(filename.c_str());
+  std::ifstream fin(filename);
   if (!fin) {
-    throw BadFile();
+    throw BadFile(filename);
   }
   return Load(fin);
 }
@@ -51,7 +51,7 @@ std::vector<Node> LoadAll(std::istream& input) {
   std::vector<Node> docs;
 
   Parser parser(input);
-  while (1) {
+  while (true) {
     NodeBuilder builder;
     if (!parser.HandleNextDocument(builder)) {
       break;
@@ -63,9 +63,9 @@ std::vector<Node> LoadAll(std::istream& input) {
 }
 
 std::vector<Node> LoadAllFromFile(const std::string& filename) {
-  std::ifstream fin(filename.c_str());
+  std::ifstream fin(filename);
   if (!fin) {
-    throw BadFile();
+    throw BadFile(filename);
   }
   return LoadAll(fin);
 }

src/parser.cpp

@@ -17,9 +17,7 @@ Parser::Parser(std::istream& in) : Parser() { Load(in); }
 
 Parser::~Parser() = default;
 
-Parser::operator bool() const {
-  return m_pScanner && !m_pScanner->empty();
-}
+Parser::operator bool() const { return m_pScanner && !m_pScanner->empty(); }
 
 void Parser::Load(std::istream& in) {
   m_pScanner.reset(new Scanner(in));

src/scanner.cpp

@@ -51,7 +51,7 @@ Token& Scanner::peek() {
 Mark Scanner::mark() const { return INPUT.mark(); }
 
 void Scanner::EnsureTokensInQueue() {
-  while (1) {
+  while (true) {
     if (!m_tokens.empty()) {
       Token& token = m_tokens.front();
 
@@ -88,7 +88,7 @@ void Scanner::ScanNextToken() {
     return StartStream();
   }
 
-  // get rid of whitespace, etc. (in between tokens it should be irrelevent)
+  // get rid of whitespace, etc. (in between tokens it should be irrelevant)
   ScanToNextToken();
 
   // maybe need to end some blocks
@@ -174,7 +174,7 @@ void Scanner::ScanNextToken() {
 }
 
 void Scanner::ScanToNextToken() {
-  while (1) {
+  while (true) {
     // first eat whitespace
     while (INPUT && IsWhitespaceToBeEaten(INPUT.peek())) {
       if (InBlockContext() && Exp::Tab().Matches(INPUT)) {

src/scanner.h

@@ -9,9 +9,7 @@
 
 #include <cstddef>
 #include <ios>
-#include <map>
 #include <queue>
-#include <set>
 #include <stack>
 #include <string>
 

src/scanscalar.cpp

@@ -47,7 +47,8 @@ std::string ScanScalar(Stream& INPUT, ScanScalarParams& params) {
       if (INPUT.column() == 0 && Exp::DocIndicator().Matches(INPUT)) {
         if (params.onDocIndicator == BREAK) {
           break;
-        } else if (params.onDocIndicator == THROW) {
+        }
+        if (params.onDocIndicator == THROW) {
           throw ParserException(INPUT.mark(), ErrorMsg::DOC_IN_SCALAR);
         }
       }
@@ -203,7 +204,7 @@ std::string ScanScalar(Stream& INPUT, ScanScalarParams& params) {
 
   // post-processing
   if (params.trimTrailingSpaces) {
-    std::size_t pos = scalar.find_last_not_of(' ');
+    std::size_t pos = scalar.find_last_not_of(" \t");
     if (lastEscapedChar != std::string::npos) {
       if (pos < lastEscapedChar || pos == std::string::npos) {
         pos = lastEscapedChar;
@@ -247,4 +248,4 @@ std::string ScanScalar(Stream& INPUT, ScanScalarParams& params) {
 
   return scalar;
 }
-}
+}  // namespace YAML

src/scanscalar.h

@@ -57,7 +57,7 @@ struct ScanScalarParams {
   bool leadingSpaces;
 };
 
-std::string ScanScalar(Stream& INPUT, ScanScalarParams& info);
+std::string ScanScalar(Stream& INPUT, ScanScalarParams& params);
 }
 
 #endif  // SCANSCALAR_H_62B23520_7C8E_11DE_8A39_0800200C9A66

src/scantag.cpp

@@ -78,4 +78,4 @@ const std::string ScanTagSuffix(Stream& INPUT) {
 
   return tag;
 }
-}
+}  // namespace YAML

src/scantoken.cpp

@@ -37,7 +37,7 @@ void Scanner::ScanDirective() {
     token.value += INPUT.get();
 
   // read parameters
-  while (1) {
+  while (true) {
     // first get rid of whitespace
     while (Exp::Blank().Matches(INPUT))
       INPUT.eat(1);
@@ -171,7 +171,7 @@ void Scanner::ScanBlockEntry() {
 
 // Key
 void Scanner::ScanKey() {
-  // handle keys diffently in the block context (and manage indents)
+  // handle keys differently in the block context (and manage indents)
   if (InBlockContext()) {
     if (!m_simpleKeyAllowed)
       throw ParserException(INPUT.mark(), ErrorMsg::MAP_KEY);
@@ -199,7 +199,7 @@ void Scanner::ScanValue() {
     // seems fine)
     m_simpleKeyAllowed = false;
   } else {
-    // handle values diffently in the block context (and manage indents)
+    // handle values differently in the block context (and manage indents)
     if (InBlockContext()) {
       if (!m_simpleKeyAllowed)
         throw ParserException(INPUT.mark(), ErrorMsg::MAP_VALUE);

src/setting.h

@@ -83,9 +83,8 @@ class SettingChanges {
   }
 
   void restore() YAML_CPP_NOEXCEPT {
-    for (setting_changes::const_iterator it = m_settingChanges.begin();
-         it != m_settingChanges.end(); ++it)
-      (*it)->pop();
+    for (const auto& setting : m_settingChanges)
+      setting->pop();
   }
 
   void push(std::unique_ptr<SettingChangeBase> pSettingChange) {

src/simplekey.cpp

@@ -5,7 +5,11 @@ namespace YAML {
 struct Mark;
 
 Scanner::SimpleKey::SimpleKey(const Mark& mark_, std::size_t flowLevel_)
-    : mark(mark_), flowLevel(flowLevel_), pIndent(nullptr), pMapStart(nullptr), pKey(nullptr) {}
+    : mark(mark_),
+      flowLevel(flowLevel_),
+      pIndent(nullptr),
+      pMapStart(nullptr),
+      pKey(nullptr) {}
 
 void Scanner::SimpleKey::Validate() {
   // Note: pIndent will *not* be garbage here;
@@ -125,4 +129,4 @@ void Scanner::PopAllSimpleKeys() {
   while (!m_simpleKeys.empty())
     m_simpleKeys.pop();
 }
-}
+}  // namespace YAML

src/singledocparser.cpp

@@ -7,6 +7,7 @@
 #include "singledocparser.h"
 #include "tag.h"
 #include "token.h"
+#include "yaml-cpp/depthguard.h"
 #include "yaml-cpp/emitterstyle.h"
 #include "yaml-cpp/eventhandler.h"
 #include "yaml-cpp/exceptions.h"  // IWYU pragma: keep
@@ -47,6 +48,8 @@ void SingleDocParser::HandleDocument(EventHandler& eventHandler) {
 }
 
 void SingleDocParser::HandleNode(EventHandler& eventHandler) {
+  DepthGuard<500> depthguard(depth, m_scanner.mark(), ErrorMsg::BAD_FILE);
+
   // an empty node *is* a possibility
   if (m_scanner.empty()) {
     eventHandler.OnNull(m_scanner.mark(), NullAnchor);
@@ -87,16 +90,17 @@ void SingleDocParser::HandleNode(EventHandler& eventHandler) {
 
   const Token& token = m_scanner.peek();
 
-  if (token.type == Token::PLAIN_SCALAR && IsNullString(token.value)) {
+  // add non-specific tags
+  if (tag.empty())
+    tag = (token.type == Token::NON_PLAIN_SCALAR ? "!" : "?");
+  
+  if (token.type == Token::PLAIN_SCALAR 
+      && tag.compare("?") == 0 && IsNullString(token.value)) {
     eventHandler.OnNull(mark, anchor);
     m_scanner.pop();
     return;
   }
 
-  // add non-specific tags
-  if (tag.empty())
-    tag = (token.type == Token::NON_PLAIN_SCALAR ? "!" : "?");
-
   // now split based on what kind of node we should be
   switch (token.type) {
     case Token::PLAIN_SCALAR:
@@ -163,7 +167,7 @@ void SingleDocParser::HandleBlockSequence(EventHandler& eventHandler) {
   m_scanner.pop();
   m_pCollectionStack->PushCollectionType(CollectionType::BlockSeq);
 
-  while (1) {
+  while (true) {
     if (m_scanner.empty())
       throw ParserException(m_scanner.mark(), ErrorMsg::END_OF_SEQ);
 
@@ -196,7 +200,7 @@ void SingleDocParser::HandleFlowSequence(EventHandler& eventHandler) {
   m_scanner.pop();
   m_pCollectionStack->PushCollectionType(CollectionType::FlowSeq);
 
-  while (1) {
+  while (true) {
     if (m_scanner.empty())
       throw ParserException(m_scanner.mark(), ErrorMsg::END_OF_SEQ_FLOW);
 
@@ -249,7 +253,7 @@ void SingleDocParser::HandleBlockMap(EventHandler& eventHandler) {
   m_scanner.pop();
   m_pCollectionStack->PushCollectionType(CollectionType::BlockMap);
 
-  while (1) {
+  while (true) {
     if (m_scanner.empty())
       throw ParserException(m_scanner.mark(), ErrorMsg::END_OF_MAP);
 
@@ -288,7 +292,7 @@ void SingleDocParser::HandleFlowMap(EventHandler& eventHandler) {
   m_scanner.pop();
   m_pCollectionStack->PushCollectionType(CollectionType::FlowMap);
 
-  while (1) {
+  while (true) {
     if (m_scanner.empty())
       throw ParserException(m_scanner.mark(), ErrorMsg::END_OF_MAP_FLOW);
 
@@ -373,7 +377,7 @@ void SingleDocParser::ParseProperties(std::string& tag, anchor_t& anchor,
   anchor_name.clear();
   anchor = NullAnchor;
 
-  while (1) {
+  while (true) {
     if (m_scanner.empty())
       return;
 
@@ -419,9 +423,12 @@ anchor_t SingleDocParser::RegisterAnchor(const std::string& name) {
 
 anchor_t SingleDocParser::LookupAnchor(const Mark& mark,
                                        const std::string& name) const {
-  Anchors::const_iterator it = m_anchors.find(name);
-  if (it == m_anchors.end())
-    throw ParserException(mark, ErrorMsg::UNKNOWN_ANCHOR);
+  auto it = m_anchors.find(name);
+  if (it == m_anchors.end()) {
+    std::stringstream ss;
+    ss << ErrorMsg::UNKNOWN_ANCHOR << name;
+    throw ParserException(mark, ss.str());
+  }
 
   return it->second;
 }

src/singledocparser.h

@@ -15,6 +15,7 @@
 
 namespace YAML {
 class CollectionStack;
+template <int> class DepthGuard; // depthguard.h
 class EventHandler;
 class Node;
 class Scanner;
@@ -55,6 +56,7 @@ class SingleDocParser {
   anchor_t LookupAnchor(const Mark& mark, const std::string& name) const;
 
  private:
+  int depth = 0;
   Scanner& m_scanner;
   const Directives& m_directives;
   std::unique_ptr<CollectionStack> m_pCollectionStack;

src/stream.cpp

@@ -151,7 +151,8 @@ inline UtfIntroCharType IntroCharTypeOf(std::istream::int_type ch) {
 
 inline char Utf8Adjust(unsigned long ch, unsigned char lead_bits,
                        unsigned char rshift) {
-  const unsigned char header = static_cast<unsigned char>(((1 << lead_bits) - 1) << (8 - lead_bits));
+  const unsigned char header =
+      static_cast<unsigned char>(((1 << lead_bits) - 1) << (8 - lead_bits));
   const unsigned char mask = (0xFF >> (lead_bits + 1));
   return static_cast<char>(
       static_cast<unsigned char>(header | ((ch >> rshift) & mask)));
@@ -273,7 +274,7 @@ char Stream::get() {
 // . Extracts 'n' characters from the stream and updates our position
 std::string Stream::get(int n) {
   std::string ret;
-  if(n > 0) {
+  if (n > 0) {
     ret.reserve(static_cast<std::string::size_type>(n));
     for (int i = 0; i < n; i++)
       ret += get();
@@ -349,7 +350,9 @@ void Stream::StreamInUtf16() const {
     // Trailing (low) surrogate...ugh, wrong order
     QueueUnicodeCodepoint(m_readahead, CP_REPLACEMENT_CHARACTER);
     return;
-  } else if (ch >= 0xD800 && ch < 0xDC00) {
+  }
+
+  if (ch >= 0xD800 && ch < 0xDC00) {
     // ch is a leading (high) surrogate
 
     // Four byte UTF-8 code point
@@ -374,11 +377,10 @@ void Stream::StreamInUtf16() const {
           // Easiest case: queue the codepoint and return
           QueueUnicodeCodepoint(m_readahead, ch);
           return;
-        } else {
-          // Start the loop over with the new high surrogate
-          ch = chLow;
-          continue;
         }
+        // Start the loop over with the new high surrogate
+        ch = chLow;
+        continue;
       }
 
       // Select the payload bits from the high surrogate

src/tag.cpp

@@ -29,7 +29,7 @@ Tag::Tag(const Token& token)
   }
 }
 
-const std::string Tag::Translate(const Directives& directives) {
+std::string Tag::Translate(const Directives& directives) {
   switch (type) {
     case VERBATIM:
       return value;

src/tag.h

@@ -23,7 +23,7 @@ struct Tag {
   };
 
   Tag(const Token& token);
-  const std::string Translate(const Directives& directives);
+  std::string Translate(const Directives& directives);
 
   TYPE type;
   std::string handle, value;

test/CMakeLists.txt

@@ -5,10 +5,10 @@ set(BUILD_MOCK ON CACHE BOOL "" FORCE)
 set(CMAKE_POLICY_DEFAULT_CMP0048 NEW)
 
 add_subdirectory(
-  "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.8.0"
+  "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.11.0"
   "${CMAKE_CURRENT_BINARY_DIR}/prefix")
 
-include_directories(SYSTEM "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.8.0/googletest/include")
+include_directories(SYSTEM "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.11.0/googletest/include")
 
 set(test-new-api-pattern "new-api/*.cpp")
 set(test-source-pattern "*.cpp" "integration/*.cpp" "node/*.cpp")
@@ -33,7 +33,7 @@ target_include_directories(yaml-cpp-tests
 target_compile_options(yaml-cpp-tests
   PRIVATE
     $<$<CXX_COMPILER_ID:Clang>:-Wno-c99-extensions -Wno-variadic-macros -Wno-sign-compare>
-    $<$<CXX_COMPILER_ID:GNU>:-Wno-variadic-macros -Wno-sign-compare>)
+    $<$<CXX_COMPILER_ID:GNU>:-Wno-variadic-macros -Wno-sign-compare -Wno-narrowing>)
 target_link_libraries(yaml-cpp-tests
   PRIVATE
     Threads::Threads
@@ -46,4 +46,11 @@ if (NOT DEFINED CMAKE_CXX_STANDARD)
 endif()
 
 
-add_test(yaml-cpp::test yaml-cpp-tests)
+add_test(NAME yaml-cpp::test COMMAND yaml-cpp-tests)
+
+if (build-windows-dll)
+  add_custom_command(
+    TARGET yaml-cpp-tests
+    POST_BUILD COMMAND ${CMAKE_COMMAND} -E
+    copy_if_different "$<TARGET_FILE:yaml-cpp>" "$<TARGET_FILE_DIR:yaml-cpp-tests>")
+endif()

test/binary_test.cpp

@@ -0,0 +1,14 @@
+#include "gtest/gtest.h"
+#include <yaml-cpp/binary.h>
+
+TEST(BinaryTest, DecodingSimple) {
+  std::string input{90, 71, 86, 104, 90, 71, 74, 108, 90, 87, 89, 61};
+  const std::vector<unsigned char> &result = YAML::DecodeBase64(input);
+  EXPECT_EQ(std::string(result.begin(), result.end()), "deadbeef");
+}
+
+TEST(BinaryTest, DecodingNoCrashOnNegative) {
+  std::string input{-58, -1, -99, 109};
+  const std::vector<unsigned char> &result = YAML::DecodeBase64(input);
+  EXPECT_TRUE(result.empty());
+}

test/gtest-1.11.0/.clang-format

@@ -0,0 +1,4 @@
+# Run manually to reformat a file:
+# clang-format -i --style=file <file>
+Language:        Cpp
+BasedOnStyle:  Google

test/gtest-1.11.0/.github/ISSUE_TEMPLATE/00-bug_report.md

@@ -0,0 +1,43 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: 'bug'
+assignees: ''
+---
+
+**Describe the bug**
+
+Include a clear and concise description of what the problem is, including what
+you expected to happen, and what actually happened.
+
+**Steps to reproduce the bug**
+
+It's important that we are able to reproduce the problem that you are
+experiencing. Please provide all code and relevant steps to reproduce the
+problem, including your `BUILD`/`CMakeLists.txt` file and build commands. Links
+to a GitHub branch or [godbolt.org](https://godbolt.org/) that demonstrate the
+problem are also helpful.
+
+**Does the bug persist in the most recent commit?**
+
+We recommend using the latest commit in the master branch in your projects.
+
+**What operating system and version are you using?**
+
+If you are using a Linux distribution please include the name and version of the
+distribution as well.
+
+**What compiler and version are you using?**
+
+Please include the output of `gcc -v` or `clang -v`, or the equivalent for your
+compiler.
+
+**What build system are you using?**
+
+Please include the output of `bazel --version` or `cmake --version`, or the
+equivalent for your build system.
+
+**Additional context**
+
+Add any other context about the problem here.

test/gtest-1.11.0/.github/ISSUE_TEMPLATE/10-feature_request.md

@@ -0,0 +1,24 @@
+---
+name: Feature request
+about: Propose a new feature
+title: ''
+labels: 'enhancement'
+assignees: ''
+---
+
+**Does the feature exist in the most recent commit?**
+
+We recommend using the latest commit from GitHub in your projects.
+
+**Why do we need this feature?**
+
+Ideally, explain why a combination of existing features cannot be used instead.
+
+**Describe the proposal**
+
+Include a detailed description of the feature, with usage examples.
+
+**Is the feature specific to an operating system, compiler, or build system version?**
+
+If it is, please specify which versions.
+

test/gtest-1.11.0/.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1 @@
+blank_issues_enabled: false

test/gtest-1.11.0/.gitignore

@@ -0,0 +1,84 @@
+# Ignore CI build directory
+build/
+xcuserdata
+cmake-build-debug/
+.idea/
+bazel-bin
+bazel-genfiles
+bazel-googletest
+bazel-out
+bazel-testlogs
+# python
+*.pyc
+
+# Visual Studio files
+.vs
+*.sdf
+*.opensdf
+*.VC.opendb
+*.suo
+*.user
+_ReSharper.Caches/
+Win32-Debug/
+Win32-Release/
+x64-Debug/
+x64-Release/
+
+# Ignore autoconf / automake files
+Makefile.in
+aclocal.m4
+configure
+build-aux/
+autom4te.cache/
+googletest/m4/libtool.m4
+googletest/m4/ltoptions.m4
+googletest/m4/ltsugar.m4
+googletest/m4/ltversion.m4
+googletest/m4/lt~obsolete.m4
+googlemock/m4
+
+# Ignore generated directories.
+googlemock/fused-src/
+googletest/fused-src/
+
+# macOS files
+.DS_Store
+googletest/.DS_Store
+googletest/xcode/.DS_Store
+
+# Ignore cmake generated directories and files.
+CMakeFiles
+CTestTestfile.cmake
+Makefile
+cmake_install.cmake
+googlemock/CMakeFiles
+googlemock/CTestTestfile.cmake
+googlemock/Makefile
+googlemock/cmake_install.cmake
+googlemock/gtest
+/bin
+/googlemock/gmock.dir
+/googlemock/gmock_main.dir
+/googlemock/RUN_TESTS.vcxproj.filters
+/googlemock/RUN_TESTS.vcxproj
+/googlemock/INSTALL.vcxproj.filters
+/googlemock/INSTALL.vcxproj
+/googlemock/gmock_main.vcxproj.filters
+/googlemock/gmock_main.vcxproj
+/googlemock/gmock.vcxproj.filters
+/googlemock/gmock.vcxproj
+/googlemock/gmock.sln
+/googlemock/ALL_BUILD.vcxproj.filters
+/googlemock/ALL_BUILD.vcxproj
+/lib
+/Win32
+/ZERO_CHECK.vcxproj.filters
+/ZERO_CHECK.vcxproj
+/RUN_TESTS.vcxproj.filters
+/RUN_TESTS.vcxproj
+/INSTALL.vcxproj.filters
+/INSTALL.vcxproj
+/googletest-distribution.sln
+/CMakeCache.txt
+/ALL_BUILD.vcxproj.filters
+/ALL_BUILD.vcxproj

test/gtest-1.11.0/BUILD.bazel

@@ -0,0 +1,190 @@
+# Copyright 2017 Google Inc.
+# All Rights Reserved.
+#
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+#   Bazel Build for Google C++ Testing Framework(Google Test)
+
+load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+exports_files(["LICENSE"])
+
+config_setting(
+    name = "windows",
+    constraint_values = ["@platforms//os:windows"],
+)
+
+config_setting(
+    name = "msvc_compiler",
+    flag_values = {
+        "@bazel_tools//tools/cpp:compiler": "msvc-cl",
+    },
+    visibility = [":__subpackages__"],
+)
+
+config_setting(
+    name = "has_absl",
+    values = {"define": "absl=1"},
+)
+
+# Library that defines the FRIEND_TEST macro.
+cc_library(
+    name = "gtest_prod",
+    hdrs = ["googletest/include/gtest/gtest_prod.h"],
+    includes = ["googletest/include"],
+)
+
+# Google Test including Google Mock
+cc_library(
+    name = "gtest",
+    srcs = glob(
+        include = [
+            "googletest/src/*.cc",
+            "googletest/src/*.h",
+            "googletest/include/gtest/**/*.h",
+            "googlemock/src/*.cc",
+            "googlemock/include/gmock/**/*.h",
+        ],
+        exclude = [
+            "googletest/src/gtest-all.cc",
+            "googletest/src/gtest_main.cc",
+            "googlemock/src/gmock-all.cc",
+            "googlemock/src/gmock_main.cc",
+        ],
+    ),
+    hdrs = glob([
+        "googletest/include/gtest/*.h",
+        "googlemock/include/gmock/*.h",
+    ]),
+    copts = select({
+        ":windows": [],
+        "//conditions:default": ["-pthread"],
+    }),
+    defines = select({
+        ":has_absl": ["GTEST_HAS_ABSL=1"],
+        "//conditions:default": [],
+    }),
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+    includes = [
+        "googlemock",
+        "googlemock/include",
+        "googletest",
+        "googletest/include",
+    ],
+    linkopts = select({
+        ":windows": [],
+        "//conditions:default": ["-pthread"],
+    }),
+    deps = select({
+        ":has_absl": [
+            "@com_google_absl//absl/debugging:failure_signal_handler",
+            "@com_google_absl//absl/debugging:stacktrace",
+            "@com_google_absl//absl/debugging:symbolize",
+            "@com_google_absl//absl/strings",
+            "@com_google_absl//absl/types:any",
+            "@com_google_absl//absl/types:optional",
+            "@com_google_absl//absl/types:variant",
+        ],
+        "//conditions:default": [],
+    }),
+)
+
+cc_library(
+    name = "gtest_main",
+    srcs = ["googlemock/src/gmock_main.cc"],
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+    deps = [":gtest"],
+)
+
+# The following rules build samples of how to use gTest.
+cc_library(
+    name = "gtest_sample_lib",
+    srcs = [
+        "googletest/samples/sample1.cc",
+        "googletest/samples/sample2.cc",
+        "googletest/samples/sample4.cc",
+    ],
+    hdrs = [
+        "googletest/samples/prime_tables.h",
+        "googletest/samples/sample1.h",
+        "googletest/samples/sample2.h",
+        "googletest/samples/sample3-inl.h",
+        "googletest/samples/sample4.h",
+    ],
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+)
+
+cc_test(
+    name = "gtest_samples",
+    size = "small",
+    # All Samples except:
+    #   sample9 (main)
+    #   sample10 (main and takes a command line option and needs to be separate)
+    srcs = [
+        "googletest/samples/sample1_unittest.cc",
+        "googletest/samples/sample2_unittest.cc",
+        "googletest/samples/sample3_unittest.cc",
+        "googletest/samples/sample4_unittest.cc",
+        "googletest/samples/sample5_unittest.cc",
+        "googletest/samples/sample6_unittest.cc",
+        "googletest/samples/sample7_unittest.cc",
+        "googletest/samples/sample8_unittest.cc",
+    ],
+    linkstatic = 0,
+    deps = [
+        "gtest_sample_lib",
+        ":gtest_main",
+    ],
+)
+
+cc_test(
+    name = "sample9_unittest",
+    size = "small",
+    srcs = ["googletest/samples/sample9_unittest.cc"],
+    deps = [":gtest"],
+)
+
+cc_test(
+    name = "sample10_unittest",
+    size = "small",
+    srcs = ["googletest/samples/sample10_unittest.cc"],
+    deps = [":gtest"],
+)

test/gtest-1.11.0/CMakeLists.txt

@@ -0,0 +1,32 @@
+# Note: CMake support is community-based. The maintainers do not use CMake
+# internally.
+
+cmake_minimum_required(VERSION 2.8.12)
+
+if (POLICY CMP0048)
+  cmake_policy(SET CMP0048 NEW)
+endif (POLICY CMP0048)
+
+project(googletest-distribution)
+set(GOOGLETEST_VERSION 1.11.0)
+
+if (CMAKE_VERSION VERSION_GREATER "3.0.2")
+  if(NOT CYGWIN AND NOT MSYS AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL QNX)
+    set(CMAKE_CXX_EXTENSIONS OFF)
+  endif()
+endif()
+
+enable_testing()
+
+include(CMakeDependentOption)
+include(GNUInstallDirs)
+
+#Note that googlemock target already builds googletest
+option(BUILD_GMOCK "Builds the googlemock subproject" ON)
+option(INSTALL_GTEST "Enable installation of googletest. (Projects embedding googletest may want to turn this OFF.)" ON)
+
+if(BUILD_GMOCK)
+  add_subdirectory( googlemock )
+else()
+  add_subdirectory( googletest )
+endif()

test/gtest-1.11.0/CONTRIBUTING.md

@@ -0,0 +1,130 @@
+# How to become a contributor and submit your own code
+
+## Contributor License Agreements
+
+We'd love to accept your patches! Before we can take them, we have to jump a
+couple of legal hurdles.
+
+Please fill out either the individual or corporate Contributor License Agreement
+(CLA).
+
+*   If you are an individual writing original source code and you're sure you
+    own the intellectual property, then you'll need to sign an
+    [individual CLA](https://developers.google.com/open-source/cla/individual).
+*   If you work for a company that wants to allow you to contribute your work,
+    then you'll need to sign a
+    [corporate CLA](https://developers.google.com/open-source/cla/corporate).
+
+Follow either of the two links above to access the appropriate CLA and
+instructions for how to sign and return it. Once we receive it, we'll be able to
+accept your pull requests.
+
+## Are you a Googler?
+
+If you are a Googler, please make an attempt to submit an internal change rather
+than a GitHub Pull Request. If you are not able to submit an internal change a
+PR is acceptable as an alternative.
+
+## Contributing A Patch
+
+1.  Submit an issue describing your proposed change to the
+    [issue tracker](https://github.com/google/googletest/issues).
+2.  Please don't mix more than one logical change per submittal, because it
+    makes the history hard to follow. If you want to make a change that doesn't
+    have a corresponding issue in the issue tracker, please create one.
+3.  Also, coordinate with team members that are listed on the issue in question.
+    This ensures that work isn't being duplicated and communicating your plan
+    early also generally leads to better patches.
+4.  If your proposed change is accepted, and you haven't already done so, sign a
+    Contributor License Agreement (see details above).
+5.  Fork the desired repo, develop and test your code changes.
+6.  Ensure that your code adheres to the existing style in the sample to which
+    you are contributing.
+7.  Ensure that your code has an appropriate set of unit tests which all pass.
+8.  Submit a pull request.
+
+## The Google Test and Google Mock Communities
+
+The Google Test community exists primarily through the
+[discussion group](http://groups.google.com/group/googletestframework) and the
+GitHub repository. Likewise, the Google Mock community exists primarily through
+their own [discussion group](http://groups.google.com/group/googlemock). You are
+definitely encouraged to contribute to the discussion and you can also help us
+to keep the effectiveness of the group high by following and promoting the
+guidelines listed here.
+
+### Please Be Friendly
+
+Showing courtesy and respect to others is a vital part of the Google culture,
+and we strongly encourage everyone participating in Google Test development to
+join us in accepting nothing less. Of course, being courteous is not the same as
+failing to constructively disagree with each other, but it does mean that we
+should be respectful of each other when enumerating the 42 technical reasons
+that a particular proposal may not be the best choice. There's never a reason to
+be antagonistic or dismissive toward anyone who is sincerely trying to
+contribute to a discussion.
+
+Sure, C++ testing is serious business and all that, but it's also a lot of fun.
+Let's keep it that way. Let's strive to be one of the friendliest communities in
+all of open source.
+
+As always, discuss Google Test in the official GoogleTest discussion group. You
+don't have to actually submit code in order to sign up. Your participation
+itself is a valuable contribution.
+
+## Style
+
+To keep the source consistent, readable, diffable and easy to merge, we use a
+fairly rigid coding style, as defined by the
+[google-styleguide](https://github.com/google/styleguide) project. All patches
+will be expected to conform to the style outlined
+[here](https://google.github.io/styleguide/cppguide.html). Use
+[.clang-format](https://github.com/google/googletest/blob/master/.clang-format)
+to check your formatting.
+
+## Requirements for Contributors
+
+If you plan to contribute a patch, you need to build Google Test, Google Mock,
+and their own tests from a git checkout, which has further requirements:
+
+*   [Python](https://www.python.org/) v2.3 or newer (for running some of the
+    tests and re-generating certain source files from templates)
+*   [CMake](https://cmake.org/) v2.8.12 or newer
+
+## Developing Google Test and Google Mock
+
+This section discusses how to make your own changes to the Google Test project.
+
+### Testing Google Test and Google Mock Themselves
+
+To make sure your changes work as intended and don't break existing
+functionality, you'll want to compile and run Google Test and GoogleMock's own
+tests. For that you can use CMake:
+
+    mkdir mybuild
+    cd mybuild
+    cmake -Dgtest_build_tests=ON -Dgmock_build_tests=ON ${GTEST_REPO_DIR}
+
+To choose between building only Google Test or Google Mock, you may modify your
+cmake command to be one of each
+
+    cmake -Dgtest_build_tests=ON ${GTEST_DIR} # sets up Google Test tests
+    cmake -Dgmock_build_tests=ON ${GMOCK_DIR} # sets up Google Mock tests
+
+Make sure you have Python installed, as some of Google Test's tests are written
+in Python. If the cmake command complains about not being able to find Python
+(`Could NOT find PythonInterp (missing: PYTHON_EXECUTABLE)`), try telling it
+explicitly where your Python executable can be found:
+
+    cmake -DPYTHON_EXECUTABLE=path/to/python ...
+
+Next, you can build Google Test and / or Google Mock and all desired tests. On
+\*nix, this is usually done by
+
+    make
+
+To run the tests, do
+
+    make test
+
+All tests should pass.

test/gtest-1.11.0/CONTRIBUTORS

@@ -5,33 +5,59 @@
 
 Ajay Joshi <jaj@google.com>
 Balázs Dán <balazs.dan@gmail.com>
+Benoit Sigoure <tsuna@google.com>
 Bharat Mediratta <bharat@menalto.com>
+Bogdan Piloca <boo@google.com>
 Chandler Carruth <chandlerc@google.com>
 Chris Prince <cprince@google.com>
 Chris Taylor <taylorc@google.com>
 Dan Egnor <egnor@google.com>
+Dave MacLachlan <dmaclach@gmail.com>
+David Anderson <danderson@google.com>
+Dean Sturtevant
 Eric Roman <eroman@chromium.org>
+Gene Volovich <gv@cite.com>
 Hady Zalek <hady.zalek@gmail.com>
+Hal Burch <gmock@hburch.com>
 Jeffrey Yasskin <jyasskin@google.com>
+Jim Keller <jimkeller@google.com>
+Joe Walnes <joe@truemesh.com>
+Jon Wray <jwray@google.com>
 Jói Sigurðsson <joi@google.com>
 Keir Mierle <mierle@gmail.com>
 Keith Ray <keith.ray@gmail.com>
 Kenton Varda <kenton@google.com>
+Kostya Serebryany <kcc@google.com>
+Krystian Kuzniarek <krystian.kuzniarek@gmail.com>
+Lev Makhlis
 Manuel Klimek <klimek@google.com>
+Mario Tanev <radix@google.com>
+Mark Paskin
 Markus Heule <markus.heule@gmail.com>
+Matthew Simmons <simmonmt@acm.org>
 Mika Raento <mikie@iki.fi>
+Mike Bland <mbland@google.com>
 Miklós Fazekas <mfazekas@szemafor.com>
+Neal Norwitz <nnorwitz@gmail.com>
+Nermin Ozkiranartli <nermin@google.com>
+Owen Carlsen <ocarlsen@google.com>
+Paneendra Ba <paneendra@google.com>
 Pasi Valminen <pasi.valminen@gmail.com>
 Patrick Hanna <phanna@google.com>
 Patrick Riley <pfr@google.com>
+Paul Menage <menage@google.com>
 Peter Kaminski <piotrk@google.com>
+Piotr Kaminski <piotrk@google.com>
 Preston Jackson <preston.a.jackson@gmail.com>
 Rainer Klaffenboeck <rainer.klaffenboeck@dynatrace.com>
 Russ Cox <rsc@google.com>
 Russ Rufer <russ@pentad.com>
 Sean Mcafee <eefacm@gmail.com>
 Sigurður Ásgeirsson <siggi@google.com>
+Sverre Sundsdal <sundsdal@gmail.com>
+Takeshi Yoshino <tyoshino@google.com>
 Tracy Bialik <tracy@pentad.com>
 Vadim Berman <vadimb@google.com>
 Vlad Losev <vladl@google.com>
+Wolfgang Klier <wklier@google.com>
 Zhanyong Wan <wan@google.com>

test/gtest-1.11.0/README.md

@@ -0,0 +1,140 @@
+# GoogleTest
+
+### Announcements
+
+#### Live at Head
+
+GoogleTest now follows the
+[Abseil Live at Head philosophy](https://abseil.io/about/philosophy#upgrade-support).
+We recommend using the latest commit in the `master` branch in your projects.
+
+#### Documentation Updates
+
+Our documentation is now live on GitHub Pages at
+https://google.github.io/googletest/. We recommend browsing the documentation on
+GitHub Pages rather than directly in the repository.
+
+#### Release 1.10.x
+
+[Release 1.10.x](https://github.com/google/googletest/releases/tag/release-1.10.0)
+is now available.
+
+#### Coming Soon
+
+*   We are planning to take a dependency on
+    [Abseil](https://github.com/abseil/abseil-cpp).
+*   More documentation improvements are planned.
+
+## Welcome to **GoogleTest**, Google's C++ test framework!
+
+This repository is a merger of the formerly separate GoogleTest and GoogleMock
+projects. These were so closely related that it makes sense to maintain and
+release them together.
+
+### Getting Started
+
+See the [GoogleTest User's Guide](https://google.github.io/googletest/) for
+documentation. We recommend starting with the
+[GoogleTest Primer](https://google.github.io/googletest/primer.html).
+
+More information about building GoogleTest can be found at
+[googletest/README.md](googletest/README.md).
+
+## Features
+
+*   An [xUnit](https://en.wikipedia.org/wiki/XUnit) test framework.
+*   Test discovery.
+*   A rich set of assertions.
+*   User-defined assertions.
+*   Death tests.
+*   Fatal and non-fatal failures.
+*   Value-parameterized tests.
+*   Type-parameterized tests.
+*   Various options for running the tests.
+*   XML test report generation.
+
+## Supported Platforms
+
+GoogleTest requires a codebase and compiler compliant with the C++11 standard or
+newer.
+
+The GoogleTest code is officially supported on the following platforms.
+Operating systems or tools not listed below are community-supported. For
+community-supported platforms, patches that do not complicate the code may be
+considered.
+
+If you notice any problems on your platform, please file an issue on the
+[GoogleTest GitHub Issue Tracker](https://github.com/google/googletest/issues).
+Pull requests containing fixes are welcome!
+
+### Operating Systems
+
+*   Linux
+*   macOS
+*   Windows
+
+### Compilers
+
+*   gcc 5.0+
+*   clang 5.0+
+*   MSVC 2015+
+
+**macOS users:** Xcode 9.3+ provides clang 5.0+.
+
+### Build Systems
+
+*   [Bazel](https://bazel.build/)
+*   [CMake](https://cmake.org/)
+
+**Note:** Bazel is the build system used by the team internally and in tests.
+CMake is supported on a best-effort basis and by the community.
+
+## Who Is Using GoogleTest?
+
+In addition to many internal projects at Google, GoogleTest is also used by the
+following notable projects:
+
+*   The [Chromium projects](http://www.chromium.org/) (behind the Chrome browser
+    and Chrome OS).
+*   The [LLVM](http://llvm.org/) compiler.
+*   [Protocol Buffers](https://github.com/google/protobuf), Google's data
+    interchange format.
+*   The [OpenCV](http://opencv.org/) computer vision library.
+
+## Related Open Source Projects
+
+[GTest Runner](https://github.com/nholthaus/gtest-runner) is a Qt5 based
+automated test-runner and Graphical User Interface with powerful features for
+Windows and Linux platforms.
+
+[GoogleTest UI](https://github.com/ospector/gtest-gbar) is a test runner that
+runs your test binary, allows you to track its progress via a progress bar, and
+displays a list of test failures. Clicking on one shows failure text. Google
+Test UI is written in C#.
+
+[GTest TAP Listener](https://github.com/kinow/gtest-tap-listener) is an event
+listener for GoogleTest that implements the
+[TAP protocol](https://en.wikipedia.org/wiki/Test_Anything_Protocol) for test
+result output. If your test runner understands TAP, you may find it useful.
+
+[gtest-parallel](https://github.com/google/gtest-parallel) is a test runner that
+runs tests from your binary in parallel to provide significant speed-up.
+
+[GoogleTest Adapter](https://marketplace.visualstudio.com/items?itemName=DavidSchuldenfrei.gtest-adapter)
+is a VS Code extension allowing to view GoogleTest in a tree view, and run/debug
+your tests.
+
+[C++ TestMate](https://github.com/matepek/vscode-catch2-test-adapter) is a VS
+Code extension allowing to view GoogleTest in a tree view, and run/debug your
+tests.
+
+[Cornichon](https://pypi.org/project/cornichon/) is a small Gherkin DSL parser
+that generates stub code for GoogleTest.
+
+## Contributing Changes
+
+Please read
+[`CONTRIBUTING.md`](https://github.com/google/googletest/blob/master/CONTRIBUTING.md)
+for details on how to contribute to this project.
+
+Happy testing!

test/gtest-1.11.0/WORKSPACE

@@ -0,0 +1,24 @@
+workspace(name = "com_google_googletest")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "com_google_absl",
+    urls = ["https://github.com/abseil/abseil-cpp/archive/7971fb358ae376e016d2d4fc9327aad95659b25e.zip"],  # 2021-05-20T02:59:16Z
+    strip_prefix = "abseil-cpp-7971fb358ae376e016d2d4fc9327aad95659b25e",
+    sha256 = "aeba534f7307e36fe084b452299e49b97420667a8d28102cf9a0daeed340b859",
+)
+
+http_archive(
+  name = "rules_cc",
+  urls = ["https://github.com/bazelbuild/rules_cc/archive/68cb652a71e7e7e2858c50593e5a9e3b94e5b9a9.zip"],  # 2021-05-14T14:51:14Z
+  strip_prefix = "rules_cc-68cb652a71e7e7e2858c50593e5a9e3b94e5b9a9",
+  sha256 = "1e19e9a3bc3d4ee91d7fcad00653485ee6c798efbbf9588d40b34cbfbded143d",
+)
+
+http_archive(
+  name = "rules_python",
+  urls = ["https://github.com/bazelbuild/rules_python/archive/ed6cc8f2c3692a6a7f013ff8bc185ba77eb9b4d2.zip"],  # 2021-05-17T00:24:16Z
+  strip_prefix = "rules_python-ed6cc8f2c3692a6a7f013ff8bc185ba77eb9b4d2",
+  sha256 = "98b3c592faea9636ac8444bfd9de7f3fb4c60590932d6e6ac5946e3f8dbd5ff6",
+)

test/gtest-1.11.0/ci/linux-presubmit.sh

@@ -0,0 +1,126 @@
+#!/bin/bash
+#
+# Copyright 2020, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -euox pipefail
+
+readonly LINUX_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20210525"
+readonly LINUX_GCC_FLOOR_CONTAINER="gcr.io/google.com/absl-177019/linux_gcc-floor:20201015"
+
+if [[ -z ${GTEST_ROOT:-} ]]; then
+  GTEST_ROOT="$(realpath $(dirname ${0})/..)"
+fi
+
+if [[ -z ${STD:-} ]]; then
+  STD="c++11 c++14 c++17 c++20"
+fi
+
+# Test the CMake build
+for cc in /usr/local/bin/gcc /opt/llvm/clang/bin/clang; do
+  for cmake_off_on in OFF ON; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --tmpfs="/build:exec" \
+      --workdir="/build" \
+      --rm \
+      --env="CC=${cc}" \
+      --env="CXX_FLAGS=\"-Werror -Wdeprecated\"" \
+      ${LINUX_LATEST_CONTAINER} \
+      /bin/bash -c "
+        cmake /src \
+          -DCMAKE_CXX_STANDARD=11 \
+          -Dgtest_build_samples=ON \
+          -Dgtest_build_tests=ON \
+          -Dgmock_build_tests=ON \
+          -Dcxx_no_exception=${cmake_off_on} \
+          -Dcxx_no_rtti=${cmake_off_on} && \
+        make -j$(nproc) && \
+        ctest -j$(nproc) --output-on-failure"
+  done
+done
+
+# Do one test with an older version of GCC
+time docker run \
+  --volume="${GTEST_ROOT}:/src:ro" \
+  --workdir="/src" \
+  --rm \
+  --env="CC=/usr/local/bin/gcc" \
+  ${LINUX_GCC_FLOOR_CONTAINER} \
+    /usr/local/bin/bazel test ... \
+      --copt="-Wall" \
+      --copt="-Werror" \
+      --copt="-Wno-error=pragmas" \
+      --keep_going \
+      --show_timestamps \
+      --test_output=errors
+
+# Test GCC
+for std in ${STD}; do
+  for absl in 0 1; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --workdir="/src" \
+      --rm \
+      --env="CC=/usr/local/bin/gcc" \
+      --env="BAZEL_CXXOPTS=-std=${std}" \
+      ${LINUX_LATEST_CONTAINER} \
+      /usr/local/bin/bazel test ... \
+        --copt="-Wall" \
+        --copt="-Werror" \
+        --define="absl=${absl}" \
+        --distdir="/bazel-distdir" \
+        --keep_going \
+        --show_timestamps \
+        --test_output=errors
+  done
+done
+
+# Test Clang
+for std in ${STD}; do
+  for absl in 0 1; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --workdir="/src" \
+      --rm \
+      --env="CC=/opt/llvm/clang/bin/clang" \
+      --env="BAZEL_CXXOPTS=-std=${std}" \
+      ${LINUX_LATEST_CONTAINER} \
+      /usr/local/bin/bazel test ... \
+        --copt="--gcc-toolchain=/usr/local" \
+        --copt="-Wall" \
+        --copt="-Werror" \
+        --define="absl=${absl}" \
+        --distdir="/bazel-distdir" \
+        --keep_going \
+        --linkopt="--gcc-toolchain=/usr/local" \
+        --show_timestamps \
+        --test_output=errors
+  done
+done

test/gtest-1.11.0/ci/macos-presubmit.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 #
-# Copyright 2008, Google Inc.
+# Copyright 2020, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -29,37 +29,45 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-# Executes the samples and tests for the Google Test Framework.
+set -euox pipefail
 
-# Help the dynamic linker find the path to the libraries.
-export DYLD_FRAMEWORK_PATH=$BUILT_PRODUCTS_DIR
-export DYLD_LIBRARY_PATH=$BUILT_PRODUCTS_DIR
+if [[ -z ${GTEST_ROOT:-} ]]; then
+  GTEST_ROOT="$(realpath $(dirname ${0})/..)"
+fi
 
-# Create some executables.
-test_executables=("$BUILT_PRODUCTS_DIR/gtest_unittest-framework"
-                  "$BUILT_PRODUCTS_DIR/gtest_unittest"
-                  "$BUILT_PRODUCTS_DIR/sample1_unittest-framework"
-                  "$BUILT_PRODUCTS_DIR/sample1_unittest-static")
-
-# Now execute each one in turn keeping track of how many succeeded and failed. 
-succeeded=0
-failed=0
-failed_list=()
-for test in ${test_executables[*]}; do
-  "$test"
-  result=$?
-  if [ $result -eq 0 ]; then
-    succeeded=$(( $succeeded + 1 ))
-  else
-    failed=$(( failed + 1 ))
-    failed_list="$failed_list $test"
-  fi
+# Test the CMake build
+for cmake_off_on in OFF ON; do
+  BUILD_DIR=$(mktemp -d build_dir.XXXXXXXX)
+  cd ${BUILD_DIR}
+  time cmake ${GTEST_ROOT} \
+    -DCMAKE_CXX_STANDARD=11 \
+    -Dgtest_build_samples=ON \
+    -Dgtest_build_tests=ON \
+    -Dgmock_build_tests=ON \
+    -Dcxx_no_exception=${cmake_off_on} \
+    -Dcxx_no_rtti=${cmake_off_on}
+  time make
+  time ctest -j$(nproc) --output-on-failure
 done
 
-# Report the successes and failures to the console.
-echo "Tests complete with $succeeded successes and $failed failures."
-if [ $failed -ne 0 ]; then
-  echo "The following tests failed:"
-  echo $failed_list
+# Test the Bazel build
+
+# If we are running on Kokoro, check for a versioned Bazel binary.
+KOKORO_GFILE_BAZEL_BIN="bazel-3.7.0-darwin-x86_64"
+if [[ ${KOKORO_GFILE_DIR:-} ]] && [[ -f ${KOKORO_GFILE_DIR}/${KOKORO_GFILE_BAZEL_BIN} ]]; then
+  BAZEL_BIN="${KOKORO_GFILE_DIR}/${KOKORO_GFILE_BAZEL_BIN}"
+  chmod +x ${BAZEL_BIN}
+else
+  BAZEL_BIN="bazel"
 fi
-exit $failed
+
+cd ${GTEST_ROOT}
+for absl in 0 1; do
+  ${BAZEL_BIN} test ... \
+    --copt="-Wall" \
+    --copt="-Werror" \
+    --define="absl=${absl}" \
+    --keep_going \
+    --show_timestamps \
+    --test_output=errors
+done

test/gtest-1.11.0/docs/_config.yml

@@ -0,0 +1 @@
+title: GoogleTest

test/gtest-1.11.0/docs/_data/navigation.yml

@@ -0,0 +1,43 @@
+nav:
+- section: "Get Started"
+  items:
+  - title: "Supported Platforms"
+    url: "/platforms.html"
+  - title: "Quickstart: Bazel"
+    url: "/quickstart-bazel.html"
+  - title: "Quickstart: CMake"
+    url: "/quickstart-cmake.html"
+- section: "Guides"
+  items:
+  - title: "GoogleTest Primer"
+    url: "/primer.html"
+  - title: "Advanced Topics"
+    url: "/advanced.html"
+  - title: "Mocking for Dummies"
+    url: "/gmock_for_dummies.html"
+  - title: "Mocking Cookbook"
+    url: "/gmock_cook_book.html"
+  - title: "Mocking Cheat Sheet"
+    url: "/gmock_cheat_sheet.html"
+- section: "References"
+  items:
+  - title: "Testing Reference"
+    url: "/reference/testing.html"
+  - title: "Mocking Reference"
+    url: "/reference/mocking.html"
+  - title: "Assertions"
+    url: "/reference/assertions.html"
+  - title: "Matchers"
+    url: "/reference/matchers.html"
+  - title: "Actions"
+    url: "/reference/actions.html"
+  - title: "Testing FAQ"
+    url: "/faq.html"
+  - title: "Mocking FAQ"
+    url: "/gmock_faq.html"
+  - title: "Code Samples"
+    url: "/samples.html"
+  - title: "Using pkg-config"
+    url: "/pkgconfig.html"
+  - title: "Community Documentation"
+    url: "/community_created_documentation.html"

test/gtest-1.11.0/docs/_layouts/default.html

@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html lang="{{ site.lang | default: "en-US" }}">
+  <head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+
+{% seo %}
+    <link rel="stylesheet" href="{{ "/assets/css/style.css?v=" | append: site.github.build_revision | relative_url }}">
+    <script>
+      window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
+      ga('create', 'UA-197576187-1', { 'storage': 'none' });
+      ga('set', 'referrer', document.referrer.split('?')[0]);
+      ga('set', 'location', window.location.href.split('?')[0]);
+      ga('set', 'anonymizeIp', true);
+      ga('send', 'pageview');
+    </script>
+    <script async src='https://www.google-analytics.com/analytics.js'></script>
+  </head>
+  <body>
+    <div class="sidebar">
+      <div class="header">
+        <h1><a href="{{ "/" | relative_url }}">{{ site.title | default: "Documentation" }}</a></h1>
+      </div>
+      <input type="checkbox" id="nav-toggle" class="nav-toggle">
+      <label for="nav-toggle" class="expander">
+        <span class="arrow"></span>
+      </label>
+      <nav>
+        {% for item in site.data.navigation.nav %}
+        <h2>{{ item.section }}</h2>
+        <ul>
+          {% for subitem in item.items %}
+          <a href="{{subitem.url | relative_url }}">
+            <li class="{% if subitem.url == page.url %}active{% endif %}">
+              {{ subitem.title }}
+            </li>
+          </a>
+          {% endfor %}
+        </ul>
+        {% endfor %}
+      </nav>
+    </div>
+    <div class="main markdown-body">
+      <div class="main-inner">
+        {{ content }}
+      </div>
+      <div class="footer">
+        GoogleTest &middot;
+        <a href="https://github.com/google/googletest">GitHub Repository</a> &middot;
+        <a href="https://github.com/google/googletest/blob/master/LICENSE">License</a> &middot;
+        <a href="https://policies.google.com/privacy">Privacy Policy</a>
+      </div>
+    </div>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/anchor-js/4.1.0/anchor.min.js" integrity="sha256-lZaRhKri35AyJSypXXs4o6OPFTbTmUoltBbDCbdzegg=" crossorigin="anonymous"></script>
+    <script>anchors.add('.main h2, .main h3, .main h4, .main h5, .main h6');</script>
+  </body>
+</html>

test/gtest-1.11.0/docs/_sass/main.scss

@@ -0,0 +1,200 @@
+// Styles for GoogleTest docs website on GitHub Pages.
+// Color variables are defined in
+// https://github.com/pages-themes/primer/tree/master/_sass/primer-support/lib/variables
+
+$sidebar-width: 260px;
+
+body {
+  display: flex;
+  margin: 0;
+}
+
+.sidebar {
+  background: $black;
+  color: $text-white;
+  flex-shrink: 0;
+  height: 100vh;
+  overflow: auto;
+  position: sticky;
+  top: 0;
+  width: $sidebar-width;
+}
+
+.sidebar h1 {
+  font-size: 1.5em;
+}
+
+.sidebar h2 {
+  color: $gray-light;
+  font-size: 0.8em;
+  font-weight: normal;
+  margin-bottom: 0.8em;
+  padding-left: 2.5em;
+  text-transform: uppercase;
+}
+
+.sidebar .header {
+  background: $black;
+  padding: 2em;
+  position: sticky;
+  top: 0;
+  width: 100%;
+}
+
+.sidebar .header a {
+  color: $text-white;
+  text-decoration: none;
+}
+
+.sidebar .nav-toggle {
+  display: none;
+}
+
+.sidebar .expander {
+  cursor: pointer;
+  display: none;
+  height: 3em;
+  position: absolute;
+  right: 1em;
+  top: 1.5em;
+  width: 3em;
+}
+
+.sidebar .expander .arrow {
+  border: solid $white;
+  border-width: 0 3px 3px 0;
+  display: block;
+  height: 0.7em;
+  margin: 1em auto;
+  transform: rotate(45deg);
+  transition: transform 0.5s;
+  width: 0.7em;
+}
+
+.sidebar nav {
+  width: 100%;
+}
+
+.sidebar nav ul {
+  list-style-type: none;
+  margin-bottom: 1em;
+  padding: 0;
+
+  &:last-child {
+    margin-bottom: 2em;
+  }
+
+  a {
+   text-decoration: none;
+  }
+
+  li {
+    color: $text-white;
+    padding-left: 2em;
+    text-decoration: none;
+  }
+
+  li.active {
+    background: $border-gray-darker;
+    font-weight: bold;
+  }
+
+  li:hover {
+    background: $border-gray-darker;
+  }
+}
+
+.main {
+  background-color: $bg-gray;
+  width: calc(100% - #{$sidebar-width});
+}
+
+.main .main-inner {
+  background-color: $white;
+  padding: 2em;
+}
+
+.main .footer {
+  margin: 0;
+  padding: 2em;
+}
+
+.main table th {
+  text-align: left;
+}
+
+.main .callout {
+  border-left: 0.25em solid $white;
+  padding: 1em;
+
+  a {
+    text-decoration: underline;
+  }
+
+  &.important {
+    background-color: $bg-yellow-light;
+    border-color: $bg-yellow;
+    color: $black;
+  }
+
+  &.note {
+    background-color: $bg-blue-light;
+    border-color: $text-blue;
+    color: $text-blue;
+  }
+
+  &.tip {
+    background-color: $green-000;
+    border-color: $green-700;
+    color: $green-700;
+  }
+
+  &.warning {
+    background-color: $red-000;
+    border-color: $text-red;
+    color: $text-red;
+  }
+}
+
+.main .good pre {
+  background-color: $bg-green-light;
+}
+
+.main .bad pre {
+  background-color: $red-000;
+}
+
+@media all and (max-width: 768px) {
+  body {
+    flex-direction: column;
+  }
+
+  .sidebar {
+    height: auto;
+    position: relative;
+    width: 100%;
+  }
+
+  .sidebar .expander {
+    display: block;
+  }
+
+  .sidebar nav {
+    height: 0;
+    overflow: hidden;
+  }
+
+  .sidebar .nav-toggle:checked {
+    & ~ nav {
+      height: auto;
+    }
+
+    & + .expander .arrow {
+      transform: rotate(-135deg);
+    }
+  }
+
+  .main {
+    width: 100%;
+  }
+}

test/gtest-1.11.0/docs/assets/css/style.scss

@@ -0,0 +1,5 @@
+---
+---
+
+@import "jekyll-theme-primer";
+@import "main";

test/gtest-1.11.0/docs/community_created_documentation.md

@@ -0,0 +1,7 @@
+# Community-Created Documentation
+
+The following is a list, in no particular order, of links to documentation
+created by the Googletest community.
+
+*   [Googlemock Insights](https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles/blob/master/googletest/insights.md),
+    by [ElectricRCAircraftGuy](https://github.com/ElectricRCAircraftGuy)

test/gtest-1.11.0/docs/faq.md

@@ -0,0 +1,693 @@
+# Googletest FAQ
+
+## Why should test suite names and test names not contain underscore?
+
+{: .callout .note}
+Note: Googletest reserves underscore (`_`) for special purpose keywords, such as
+[the `DISABLED_` prefix](advanced.md#temporarily-disabling-tests), in addition
+to the following rationale.
+
+Underscore (`_`) is special, as C++ reserves the following to be used by the
+compiler and the standard library:
+
+1.  any identifier that starts with an `_` followed by an upper-case letter, and
+2.  any identifier that contains two consecutive underscores (i.e. `__`)
+    *anywhere* in its name.
+
+User code is *prohibited* from using such identifiers.
+
+Now let's look at what this means for `TEST` and `TEST_F`.
+
+Currently `TEST(TestSuiteName, TestName)` generates a class named
+`TestSuiteName_TestName_Test`. What happens if `TestSuiteName` or `TestName`
+contains `_`?
+
+1.  If `TestSuiteName` starts with an `_` followed by an upper-case letter (say,
+    `_Foo`), we end up with `_Foo_TestName_Test`, which is reserved and thus
+    invalid.
+2.  If `TestSuiteName` ends with an `_` (say, `Foo_`), we get
+    `Foo__TestName_Test`, which is invalid.
+3.  If `TestName` starts with an `_` (say, `_Bar`), we get
+    `TestSuiteName__Bar_Test`, which is invalid.
+4.  If `TestName` ends with an `_` (say, `Bar_`), we get
+    `TestSuiteName_Bar__Test`, which is invalid.
+
+So clearly `TestSuiteName` and `TestName` cannot start or end with `_`
+(Actually, `TestSuiteName` can start with `_` -- as long as the `_` isn't
+followed by an upper-case letter. But that's getting complicated. So for
+simplicity we just say that it cannot start with `_`.).
+
+It may seem fine for `TestSuiteName` and `TestName` to contain `_` in the
+middle. However, consider this:
+
+```c++
+TEST(Time, Flies_Like_An_Arrow) { ... }
+TEST(Time_Flies, Like_An_Arrow) { ... }
+```
+
+Now, the two `TEST`s will both generate the same class
+(`Time_Flies_Like_An_Arrow_Test`). That's not good.
+
+So for simplicity, we just ask the users to avoid `_` in `TestSuiteName` and
+`TestName`. The rule is more constraining than necessary, but it's simple and
+easy to remember. It also gives googletest some wiggle room in case its
+implementation needs to change in the future.
+
+If you violate the rule, there may not be immediate consequences, but your test
+may (just may) break with a new compiler (or a new version of the compiler you
+are using) or with a new version of googletest. Therefore it's best to follow
+the rule.
+
+## Why does googletest support `EXPECT_EQ(NULL, ptr)` and `ASSERT_EQ(NULL, ptr)` but not `EXPECT_NE(NULL, ptr)` and `ASSERT_NE(NULL, ptr)`?
+
+First of all, you can use `nullptr` with each of these macros, e.g.
+`EXPECT_EQ(ptr, nullptr)`, `EXPECT_NE(ptr, nullptr)`, `ASSERT_EQ(ptr, nullptr)`,
+`ASSERT_NE(ptr, nullptr)`. This is the preferred syntax in the style guide
+because `nullptr` does not have the type problems that `NULL` does.
+
+Due to some peculiarity of C++, it requires some non-trivial template meta
+programming tricks to support using `NULL` as an argument of the `EXPECT_XX()`
+and `ASSERT_XX()` macros. Therefore we only do it where it's most needed
+(otherwise we make the implementation of googletest harder to maintain and more
+error-prone than necessary).
+
+Historically, the `EXPECT_EQ()` macro took the *expected* value as its first
+argument and the *actual* value as the second, though this argument order is now
+discouraged. It was reasonable that someone wanted
+to write `EXPECT_EQ(NULL, some_expression)`, and this indeed was requested
+several times. Therefore we implemented it.
+
+The need for `EXPECT_NE(NULL, ptr)` wasn't nearly as strong. When the assertion
+fails, you already know that `ptr` must be `NULL`, so it doesn't add any
+information to print `ptr` in this case. That means `EXPECT_TRUE(ptr != NULL)`
+works just as well.
+
+If we were to support `EXPECT_NE(NULL, ptr)`, for consistency we'd have to
+support `EXPECT_NE(ptr, NULL)` as well. This means using the template meta
+programming tricks twice in the implementation, making it even harder to
+understand and maintain. We believe the benefit doesn't justify the cost.
+
+Finally, with the growth of the gMock matcher library, we are encouraging people
+to use the unified `EXPECT_THAT(value, matcher)` syntax more often in tests. One
+significant advantage of the matcher approach is that matchers can be easily
+combined to form new matchers, while the `EXPECT_NE`, etc, macros cannot be
+easily combined. Therefore we want to invest more in the matchers than in the
+`EXPECT_XX()` macros.
+
+## I need to test that different implementations of an interface satisfy some common requirements. Should I use typed tests or value-parameterized tests?
+
+For testing various implementations of the same interface, either typed tests or
+value-parameterized tests can get it done. It's really up to you the user to
+decide which is more convenient for you, depending on your particular case. Some
+rough guidelines:
+
+*   Typed tests can be easier to write if instances of the different
+    implementations can be created the same way, modulo the type. For example,
+    if all these implementations have a public default constructor (such that
+    you can write `new TypeParam`), or if their factory functions have the same
+    form (e.g. `CreateInstance<TypeParam>()`).
+*   Value-parameterized tests can be easier to write if you need different code
+    patterns to create different implementations' instances, e.g. `new Foo` vs
+    `new Bar(5)`. To accommodate for the differences, you can write factory
+    function wrappers and pass these function pointers to the tests as their
+    parameters.
+*   When a typed test fails, the default output includes the name of the type,
+    which can help you quickly identify which implementation is wrong.
+    Value-parameterized tests only show the number of the failed iteration by
+    default. You will need to define a function that returns the iteration name
+    and pass it as the third parameter to INSTANTIATE_TEST_SUITE_P to have more
+    useful output.
+*   When using typed tests, you need to make sure you are testing against the
+    interface type, not the concrete types (in other words, you want to make
+    sure `implicit_cast<MyInterface*>(my_concrete_impl)` works, not just that
+    `my_concrete_impl` works). It's less likely to make mistakes in this area
+    when using value-parameterized tests.
+
+I hope I didn't confuse you more. :-) If you don't mind, I'd suggest you to give
+both approaches a try. Practice is a much better way to grasp the subtle
+differences between the two tools. Once you have some concrete experience, you
+can much more easily decide which one to use the next time.
+
+## I got some run-time errors about invalid proto descriptors when using `ProtocolMessageEquals`. Help!
+
+{: .callout .note}
+**Note:** `ProtocolMessageEquals` and `ProtocolMessageEquiv` are *deprecated*
+now. Please use `EqualsProto`, etc instead.
+
+`ProtocolMessageEquals` and `ProtocolMessageEquiv` were redefined recently and
+are now less tolerant of invalid protocol buffer definitions. In particular, if
+you have a `foo.proto` that doesn't fully qualify the type of a protocol message
+it references (e.g. `message<Bar>` where it should be `message<blah.Bar>`), you
+will now get run-time errors like:
+
+```
+... descriptor.cc:...] Invalid proto descriptor for file "path/to/foo.proto":
+... descriptor.cc:...]  blah.MyMessage.my_field: ".Bar" is not defined.
+```
+
+If you see this, your `.proto` file is broken and needs to be fixed by making
+the types fully qualified. The new definition of `ProtocolMessageEquals` and
+`ProtocolMessageEquiv` just happen to reveal your bug.
+
+## My death test modifies some state, but the change seems lost after the death test finishes. Why?
+
+Death tests (`EXPECT_DEATH`, etc) are executed in a sub-process s.t. the
+expected crash won't kill the test program (i.e. the parent process). As a
+result, any in-memory side effects they incur are observable in their respective
+sub-processes, but not in the parent process. You can think of them as running
+in a parallel universe, more or less.
+
+In particular, if you use mocking and the death test statement invokes some mock
+methods, the parent process will think the calls have never occurred. Therefore,
+you may want to move your `EXPECT_CALL` statements inside the `EXPECT_DEATH`
+macro.
+
+## EXPECT_EQ(htonl(blah), blah_blah) generates weird compiler errors in opt mode. Is this a googletest bug?
+
+Actually, the bug is in `htonl()`.
+
+According to `'man htonl'`, `htonl()` is a *function*, which means it's valid to
+use `htonl` as a function pointer. However, in opt mode `htonl()` is defined as
+a *macro*, which breaks this usage.
+
+Worse, the macro definition of `htonl()` uses a `gcc` extension and is *not*
+standard C++. That hacky implementation has some ad hoc limitations. In
+particular, it prevents you from writing `Foo<sizeof(htonl(x))>()`, where `Foo`
+is a template that has an integral argument.
+
+The implementation of `EXPECT_EQ(a, b)` uses `sizeof(... a ...)` inside a
+template argument, and thus doesn't compile in opt mode when `a` contains a call
+to `htonl()`. It is difficult to make `EXPECT_EQ` bypass the `htonl()` bug, as
+the solution must work with different compilers on various platforms.
+
+## The compiler complains about "undefined references" to some static const member variables, but I did define them in the class body. What's wrong?
+
+If your class has a static data member:
+
+```c++
+// foo.h
+class Foo {
+  ...
+  static const int kBar = 100;
+};
+```
+
+You also need to define it *outside* of the class body in `foo.cc`:
+
+```c++
+const int Foo::kBar;  // No initializer here.
+```
+
+Otherwise your code is **invalid C++**, and may break in unexpected ways. In
+particular, using it in googletest comparison assertions (`EXPECT_EQ`, etc) will
+generate an "undefined reference" linker error. The fact that "it used to work"
+doesn't mean it's valid. It just means that you were lucky. :-)
+
+If the declaration of the static data member is `constexpr` then it is
+implicitly an `inline` definition, and a separate definition in `foo.cc` is not
+needed:
+
+```c++
+// foo.h
+class Foo {
+  ...
+  static constexpr int kBar = 100;  // Defines kBar, no need to do it in foo.cc.
+};
+```
+
+## Can I derive a test fixture from another?
+
+Yes.
+
+Each test fixture has a corresponding and same named test suite. This means only
+one test suite can use a particular fixture. Sometimes, however, multiple test
+cases may want to use the same or slightly different fixtures. For example, you
+may want to make sure that all of a GUI library's test suites don't leak
+important system resources like fonts and brushes.
+
+In googletest, you share a fixture among test suites by putting the shared logic
+in a base test fixture, then deriving from that base a separate fixture for each
+test suite that wants to use this common logic. You then use `TEST_F()` to write
+tests using each derived fixture.
+
+Typically, your code looks like this:
+
+```c++
+// Defines a base test fixture.
+class BaseTest : public ::testing::Test {
+ protected:
+  ...
+};
+
+// Derives a fixture FooTest from BaseTest.
+class FooTest : public BaseTest {
+ protected:
+  void SetUp() override {
+    BaseTest::SetUp();  // Sets up the base fixture first.
+    ... additional set-up work ...
+  }
+
+  void TearDown() override {
+    ... clean-up work for FooTest ...
+    BaseTest::TearDown();  // Remember to tear down the base fixture
+                           // after cleaning up FooTest!
+  }
+
+  ... functions and variables for FooTest ...
+};
+
+// Tests that use the fixture FooTest.
+TEST_F(FooTest, Bar) { ... }
+TEST_F(FooTest, Baz) { ... }
+
+... additional fixtures derived from BaseTest ...
+```
+
+If necessary, you can continue to derive test fixtures from a derived fixture.
+googletest has no limit on how deep the hierarchy can be.
+
+For a complete example using derived test fixtures, see
+[sample5_unittest.cc](https://github.com/google/googletest/blob/master/googletest/samples/sample5_unittest.cc).
+
+## My compiler complains "void value not ignored as it ought to be." What does this mean?
+
+You're probably using an `ASSERT_*()` in a function that doesn't return `void`.
+`ASSERT_*()` can only be used in `void` functions, due to exceptions being
+disabled by our build system. Please see more details
+[here](advanced.md#assertion-placement).
+
+## My death test hangs (or seg-faults). How do I fix it?
+
+In googletest, death tests are run in a child process and the way they work is
+delicate. To write death tests you really need to understand how they work—see
+the details at [Death Assertions](reference/assertions.md#death) in the
+Assertions Reference.
+
+In particular, death tests don't like having multiple threads in the parent
+process. So the first thing you can try is to eliminate creating threads outside
+of `EXPECT_DEATH()`. For example, you may want to use mocks or fake objects
+instead of real ones in your tests.
+
+Sometimes this is impossible as some library you must use may be creating
+threads before `main()` is even reached. In this case, you can try to minimize
+the chance of conflicts by either moving as many activities as possible inside
+`EXPECT_DEATH()` (in the extreme case, you want to move everything inside), or
+leaving as few things as possible in it. Also, you can try to set the death test
+style to `"threadsafe"`, which is safer but slower, and see if it helps.
+
+If you go with thread-safe death tests, remember that they rerun the test
+program from the beginning in the child process. Therefore make sure your
+program can run side-by-side with itself and is deterministic.
+
+In the end, this boils down to good concurrent programming. You have to make
+sure that there are no race conditions or deadlocks in your program. No silver
+bullet - sorry!
+
+## Should I use the constructor/destructor of the test fixture or SetUp()/TearDown()? {#CtorVsSetUp}
+
+The first thing to remember is that googletest does **not** reuse the same test
+fixture object across multiple tests. For each `TEST_F`, googletest will create
+a **fresh** test fixture object, immediately call `SetUp()`, run the test body,
+call `TearDown()`, and then delete the test fixture object.
+
+When you need to write per-test set-up and tear-down logic, you have the choice
+between using the test fixture constructor/destructor or `SetUp()/TearDown()`.
+The former is usually preferred, as it has the following benefits:
+
+*   By initializing a member variable in the constructor, we have the option to
+    make it `const`, which helps prevent accidental changes to its value and
+    makes the tests more obviously correct.
+*   In case we need to subclass the test fixture class, the subclass'
+    constructor is guaranteed to call the base class' constructor *first*, and
+    the subclass' destructor is guaranteed to call the base class' destructor
+    *afterward*. With `SetUp()/TearDown()`, a subclass may make the mistake of
+    forgetting to call the base class' `SetUp()/TearDown()` or call them at the
+    wrong time.
+
+You may still want to use `SetUp()/TearDown()` in the following cases:
+
+*   C++ does not allow virtual function calls in constructors and destructors.
+    You can call a method declared as virtual, but it will not use dynamic
+    dispatch, it will use the definition from the class the constructor of which
+    is currently executing. This is because calling a virtual method before the
+    derived class constructor has a chance to run is very dangerous - the
+    virtual method might operate on uninitialized data. Therefore, if you need
+    to call a method that will be overridden in a derived class, you have to use
+    `SetUp()/TearDown()`.
+*   In the body of a constructor (or destructor), it's not possible to use the
+    `ASSERT_xx` macros. Therefore, if the set-up operation could cause a fatal
+    test failure that should prevent the test from running, it's necessary to
+    use `abort` and abort the whole test
+    executable, or to use `SetUp()` instead of a constructor.
+*   If the tear-down operation could throw an exception, you must use
+    `TearDown()` as opposed to the destructor, as throwing in a destructor leads
+    to undefined behavior and usually will kill your program right away. Note
+    that many standard libraries (like STL) may throw when exceptions are
+    enabled in the compiler. Therefore you should prefer `TearDown()` if you
+    want to write portable tests that work with or without exceptions.
+*   The googletest team is considering making the assertion macros throw on
+    platforms where exceptions are enabled (e.g. Windows, Mac OS, and Linux
+    client-side), which will eliminate the need for the user to propagate
+    failures from a subroutine to its caller. Therefore, you shouldn't use
+    googletest assertions in a destructor if your code could run on such a
+    platform.
+
+## The compiler complains "no matching function to call" when I use ASSERT_PRED*. How do I fix it?
+
+See details for [`EXPECT_PRED*`](reference/assertions.md#EXPECT_PRED) in the
+Assertions Reference.
+
+## My compiler complains about "ignoring return value" when I call RUN_ALL_TESTS(). Why?
+
+Some people had been ignoring the return value of `RUN_ALL_TESTS()`. That is,
+instead of
+
+```c++
+  return RUN_ALL_TESTS();
+```
+
+they write
+
+```c++
+  RUN_ALL_TESTS();
+```
+
+This is **wrong and dangerous**. The testing services needs to see the return
+value of `RUN_ALL_TESTS()` in order to determine if a test has passed. If your
+`main()` function ignores it, your test will be considered successful even if it
+has a googletest assertion failure. Very bad.
+
+We have decided to fix this (thanks to Michael Chastain for the idea). Now, your
+code will no longer be able to ignore `RUN_ALL_TESTS()` when compiled with
+`gcc`. If you do so, you'll get a compiler error.
+
+If you see the compiler complaining about you ignoring the return value of
+`RUN_ALL_TESTS()`, the fix is simple: just make sure its value is used as the
+return value of `main()`.
+
+But how could we introduce a change that breaks existing tests? Well, in this
+case, the code was already broken in the first place, so we didn't break it. :-)
+
+## My compiler complains that a constructor (or destructor) cannot return a value. What's going on?
+
+Due to a peculiarity of C++, in order to support the syntax for streaming
+messages to an `ASSERT_*`, e.g.
+
+```c++
+  ASSERT_EQ(1, Foo()) << "blah blah" << foo;
+```
+
+we had to give up using `ASSERT*` and `FAIL*` (but not `EXPECT*` and
+`ADD_FAILURE*`) in constructors and destructors. The workaround is to move the
+content of your constructor/destructor to a private void member function, or
+switch to `EXPECT_*()` if that works. This
+[section](advanced.md#assertion-placement) in the user's guide explains it.
+
+## My SetUp() function is not called. Why?
+
+C++ is case-sensitive. Did you spell it as `Setup()`?
+
+Similarly, sometimes people spell `SetUpTestSuite()` as `SetupTestSuite()` and
+wonder why it's never called.
+
+
+## I have several test suites which share the same test fixture logic, do I have to define a new test fixture class for each of them? This seems pretty tedious.
+
+You don't have to. Instead of
+
+```c++
+class FooTest : public BaseTest {};
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+class BarTest : public BaseTest {};
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+you can simply `typedef` the test fixtures:
+
+```c++
+typedef BaseTest FooTest;
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+typedef BaseTest BarTest;
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+## googletest output is buried in a whole bunch of LOG messages. What do I do?
+
+The googletest output is meant to be a concise and human-friendly report. If
+your test generates textual output itself, it will mix with the googletest
+output, making it hard to read. However, there is an easy solution to this
+problem.
+
+Since `LOG` messages go to stderr, we decided to let googletest output go to
+stdout. This way, you can easily separate the two using redirection. For
+example:
+
+```shell
+$ ./my_test > gtest_output.txt
+```
+
+## Why should I prefer test fixtures over global variables?
+
+There are several good reasons:
+
+1.  It's likely your test needs to change the states of its global variables.
+    This makes it difficult to keep side effects from escaping one test and
+    contaminating others, making debugging difficult. By using fixtures, each
+    test has a fresh set of variables that's different (but with the same
+    names). Thus, tests are kept independent of each other.
+2.  Global variables pollute the global namespace.
+3.  Test fixtures can be reused via subclassing, which cannot be done easily
+    with global variables. This is useful if many test suites have something in
+    common.
+
+## What can the statement argument in ASSERT_DEATH() be?
+
+`ASSERT_DEATH(statement, matcher)` (or any death assertion macro) can be used
+wherever *`statement`* is valid. So basically *`statement`* can be any C++
+statement that makes sense in the current context. In particular, it can
+reference global and/or local variables, and can be:
+
+*   a simple function call (often the case),
+*   a complex expression, or
+*   a compound statement.
+
+Some examples are shown here:
+
+```c++
+// A death test can be a simple function call.
+TEST(MyDeathTest, FunctionCall) {
+  ASSERT_DEATH(Xyz(5), "Xyz failed");
+}
+
+// Or a complex expression that references variables and functions.
+TEST(MyDeathTest, ComplexExpression) {
+  const bool c = Condition();
+  ASSERT_DEATH((c ? Func1(0) : object2.Method("test")),
+               "(Func1|Method) failed");
+}
+
+// Death assertions can be used anywhere in a function.  In
+// particular, they can be inside a loop.
+TEST(MyDeathTest, InsideLoop) {
+  // Verifies that Foo(0), Foo(1), ..., and Foo(4) all die.
+  for (int i = 0; i < 5; i++) {
+    EXPECT_DEATH_M(Foo(i), "Foo has \\d+ errors",
+                   ::testing::Message() << "where i is " << i);
+  }
+}
+
+// A death assertion can contain a compound statement.
+TEST(MyDeathTest, CompoundStatement) {
+  // Verifies that at lease one of Bar(0), Bar(1), ..., and
+  // Bar(4) dies.
+  ASSERT_DEATH({
+    for (int i = 0; i < 5; i++) {
+      Bar(i);
+    }
+  },
+  "Bar has \\d+ errors");
+}
+```
+
+## I have a fixture class `FooTest`, but `TEST_F(FooTest, Bar)` gives me error ``"no matching function for call to `FooTest::FooTest()'"``. Why?
+
+Googletest needs to be able to create objects of your test fixture class, so it
+must have a default constructor. Normally the compiler will define one for you.
+However, there are cases where you have to define your own:
+
+*   If you explicitly declare a non-default constructor for class `FooTest`
+    (`DISALLOW_EVIL_CONSTRUCTORS()` does this), then you need to define a
+    default constructor, even if it would be empty.
+*   If `FooTest` has a const non-static data member, then you have to define the
+    default constructor *and* initialize the const member in the initializer
+    list of the constructor. (Early versions of `gcc` doesn't force you to
+    initialize the const member. It's a bug that has been fixed in `gcc 4`.)
+
+## Why does ASSERT_DEATH complain about previous threads that were already joined?
+
+With the Linux pthread library, there is no turning back once you cross the line
+from a single thread to multiple threads. The first time you create a thread, a
+manager thread is created in addition, so you get 3, not 2, threads. Later when
+the thread you create joins the main thread, the thread count decrements by 1,
+but the manager thread will never be killed, so you still have 2 threads, which
+means you cannot safely run a death test.
+
+The new NPTL thread library doesn't suffer from this problem, as it doesn't
+create a manager thread. However, if you don't control which machine your test
+runs on, you shouldn't depend on this.
+
+## Why does googletest require the entire test suite, instead of individual tests, to be named *DeathTest when it uses ASSERT_DEATH?
+
+googletest does not interleave tests from different test suites. That is, it
+runs all tests in one test suite first, and then runs all tests in the next test
+suite, and so on. googletest does this because it needs to set up a test suite
+before the first test in it is run, and tear it down afterwards. Splitting up
+the test case would require multiple set-up and tear-down processes, which is
+inefficient and makes the semantics unclean.
+
+If we were to determine the order of tests based on test name instead of test
+case name, then we would have a problem with the following situation:
+
+```c++
+TEST_F(FooTest, AbcDeathTest) { ... }
+TEST_F(FooTest, Uvw) { ... }
+
+TEST_F(BarTest, DefDeathTest) { ... }
+TEST_F(BarTest, Xyz) { ... }
+```
+
+Since `FooTest.AbcDeathTest` needs to run before `BarTest.Xyz`, and we don't
+interleave tests from different test suites, we need to run all tests in the
+`FooTest` case before running any test in the `BarTest` case. This contradicts
+with the requirement to run `BarTest.DefDeathTest` before `FooTest.Uvw`.
+
+## But I don't like calling my entire test suite \*DeathTest when it contains both death tests and non-death tests. What do I do?
+
+You don't have to, but if you like, you may split up the test suite into
+`FooTest` and `FooDeathTest`, where the names make it clear that they are
+related:
+
+```c++
+class FooTest : public ::testing::Test { ... };
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+using FooDeathTest = FooTest;
+
+TEST_F(FooDeathTest, Uvw) { ... EXPECT_DEATH(...) ... }
+TEST_F(FooDeathTest, Xyz) { ... ASSERT_DEATH(...) ... }
+```
+
+## googletest prints the LOG messages in a death test's child process only when the test fails. How can I see the LOG messages when the death test succeeds?
+
+Printing the LOG messages generated by the statement inside `EXPECT_DEATH()`
+makes it harder to search for real problems in the parent's log. Therefore,
+googletest only prints them when the death test has failed.
+
+If you really need to see such LOG messages, a workaround is to temporarily
+break the death test (e.g. by changing the regex pattern it is expected to
+match). Admittedly, this is a hack. We'll consider a more permanent solution
+after the fork-and-exec-style death tests are implemented.
+
+## The compiler complains about `no match for 'operator<<'` when I use an assertion. What gives?
+
+If you use a user-defined type `FooType` in an assertion, you must make sure
+there is an `std::ostream& operator<<(std::ostream&, const FooType&)` function
+defined such that we can print a value of `FooType`.
+
+In addition, if `FooType` is declared in a name space, the `<<` operator also
+needs to be defined in the *same* name space. See
+[Tip of the Week #49](http://abseil.io/tips/49) for details.
+
+## How do I suppress the memory leak messages on Windows?
+
+Since the statically initialized googletest singleton requires allocations on
+the heap, the Visual C++ memory leak detector will report memory leaks at the
+end of the program run. The easiest way to avoid this is to use the
+`_CrtMemCheckpoint` and `_CrtMemDumpAllObjectsSince` calls to not report any
+statically initialized heap objects. See MSDN for more details and additional
+heap check/debug routines.
+
+## How can my code detect if it is running in a test?
+
+If you write code that sniffs whether it's running in a test and does different
+things accordingly, you are leaking test-only logic into production code and
+there is no easy way to ensure that the test-only code paths aren't run by
+mistake in production. Such cleverness also leads to
+[Heisenbugs](https://en.wikipedia.org/wiki/Heisenbug). Therefore we strongly
+advise against the practice, and googletest doesn't provide a way to do it.
+
+In general, the recommended way to cause the code to behave differently under
+test is [Dependency Injection](http://en.wikipedia.org/wiki/Dependency_injection). You can inject
+different functionality from the test and from the production code. Since your
+production code doesn't link in the for-test logic at all (the
+[`testonly`](http://docs.bazel.build/versions/master/be/common-definitions.html#common.testonly) attribute for BUILD targets helps to ensure
+that), there is no danger in accidentally running it.
+
+However, if you *really*, *really*, *really* have no choice, and if you follow
+the rule of ending your test program names with `_test`, you can use the
+*horrible* hack of sniffing your executable name (`argv[0]` in `main()`) to know
+whether the code is under test.
+
+## How do I temporarily disable a test?
+
+If you have a broken test that you cannot fix right away, you can add the
+`DISABLED_` prefix to its name. This will exclude it from execution. This is
+better than commenting out the code or using `#if 0`, as disabled tests are
+still compiled (and thus won't rot).
+
+To include disabled tests in test execution, just invoke the test program with
+the `--gtest_also_run_disabled_tests` flag.
+
+## Is it OK if I have two separate `TEST(Foo, Bar)` test methods defined in different namespaces?
+
+Yes.
+
+The rule is **all test methods in the same test suite must use the same fixture
+class.** This means that the following is **allowed** because both tests use the
+same fixture class (`::testing::Test`).
+
+```c++
+namespace foo {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```
+
+However, the following code is **not allowed** and will produce a runtime error
+from googletest because the test methods are using different test fixture
+classes with the same test suite name.
+
+```c++
+namespace foo {
+class CoolTest : public ::testing::Test {};  // Fixture foo::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+class CoolTest : public ::testing::Test {};  // Fixture: bar::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```

test/gtest-1.11.0/docs/gmock_cheat_sheet.md

@@ -0,0 +1,241 @@
+# gMock Cheat Sheet
+
+## Defining a Mock Class
+
+### Mocking a Normal Class {#MockClass}
+
+Given
+
+```cpp
+class Foo {
+  ...
+  virtual ~Foo();
+  virtual int GetSize() const = 0;
+  virtual string Describe(const char* name) = 0;
+  virtual string Describe(int type) = 0;
+  virtual bool Process(Bar elem, int count) = 0;
+};
+```
+
+(note that `~Foo()` **must** be virtual) we can define its mock as
+
+```cpp
+#include "gmock/gmock.h"
+
+class MockFoo : public Foo {
+  ...
+  MOCK_METHOD(int, GetSize, (), (const, override));
+  MOCK_METHOD(string, Describe, (const char* name), (override));
+  MOCK_METHOD(string, Describe, (int type), (override));
+  MOCK_METHOD(bool, Process, (Bar elem, int count), (override));
+};
+```
+
+To create a "nice" mock, which ignores all uninteresting calls, a "naggy" mock,
+which warns on all uninteresting calls, or a "strict" mock, which treats them as
+failures:
+
+```cpp
+using ::testing::NiceMock;
+using ::testing::NaggyMock;
+using ::testing::StrictMock;
+
+NiceMock<MockFoo> nice_foo;      // The type is a subclass of MockFoo.
+NaggyMock<MockFoo> naggy_foo;    // The type is a subclass of MockFoo.
+StrictMock<MockFoo> strict_foo;  // The type is a subclass of MockFoo.
+```
+
+{: .callout .note}
+**Note:** A mock object is currently naggy by default. We may make it nice by
+default in the future.
+
+### Mocking a Class Template {#MockTemplate}
+
+Class templates can be mocked just like any class.
+
+To mock
+
+```cpp
+template <typename Elem>
+class StackInterface {
+  ...
+  virtual ~StackInterface();
+  virtual int GetSize() const = 0;
+  virtual void Push(const Elem& x) = 0;
+};
+```
+
+(note that all member functions that are mocked, including `~StackInterface()`
+**must** be virtual).
+
+```cpp
+template <typename Elem>
+class MockStack : public StackInterface<Elem> {
+  ...
+  MOCK_METHOD(int, GetSize, (), (const, override));
+  MOCK_METHOD(void, Push, (const Elem& x), (override));
+};
+```
+
+### Specifying Calling Conventions for Mock Functions
+
+If your mock function doesn't use the default calling convention, you can
+specify it by adding `Calltype(convention)` to `MOCK_METHOD`'s 4th parameter.
+For example,
+
+```cpp
+  MOCK_METHOD(bool, Foo, (int n), (Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD(int, Bar, (double x, double y),
+              (const, Calltype(STDMETHODCALLTYPE)));
+```
+
+where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows.
+
+## Using Mocks in Tests {#UsingMocks}
+
+The typical work flow is:
+
+1.  Import the gMock names you need to use. All gMock symbols are in the
+    `testing` namespace unless they are macros or otherwise noted.
+2.  Create the mock objects.
+3.  Optionally, set the default actions of the mock objects.
+4.  Set your expectations on the mock objects (How will they be called? What
+    will they do?).
+5.  Exercise code that uses the mock objects; if necessary, check the result
+    using googletest assertions.
+6.  When a mock object is destructed, gMock automatically verifies that all
+    expectations on it have been satisfied.
+
+Here's an example:
+
+```cpp
+using ::testing::Return;                          // #1
+
+TEST(BarTest, DoesThis) {
+  MockFoo foo;                                    // #2
+
+  ON_CALL(foo, GetSize())                         // #3
+      .WillByDefault(Return(1));
+  // ... other default actions ...
+
+  EXPECT_CALL(foo, Describe(5))                   // #4
+      .Times(3)
+      .WillRepeatedly(Return("Category 5"));
+  // ... other expectations ...
+
+  EXPECT_EQ(MyProductionFunction(&foo), "good");  // #5
+}                                                 // #6
+```
+
+## Setting Default Actions {#OnCall}
+
+gMock has a **built-in default action** for any function that returns `void`,
+`bool`, a numeric value, or a pointer. In C++11, it will additionally returns
+the default-constructed value, if one exists for the given type.
+
+To customize the default action for functions with return type `T`, use
+[`DefaultValue<T>`](reference/mocking.md#DefaultValue). For example:
+
+```cpp
+  // Sets the default action for return type std::unique_ptr<Buzz> to
+  // creating a new Buzz every time.
+  DefaultValue<std::unique_ptr<Buzz>>::SetFactory(
+      [] { return MakeUnique<Buzz>(AccessLevel::kInternal); });
+
+  // When this fires, the default action of MakeBuzz() will run, which
+  // will return a new Buzz object.
+  EXPECT_CALL(mock_buzzer_, MakeBuzz("hello")).Times(AnyNumber());
+
+  auto buzz1 = mock_buzzer_.MakeBuzz("hello");
+  auto buzz2 = mock_buzzer_.MakeBuzz("hello");
+  EXPECT_NE(buzz1, nullptr);
+  EXPECT_NE(buzz2, nullptr);
+  EXPECT_NE(buzz1, buzz2);
+
+  // Resets the default action for return type std::unique_ptr<Buzz>,
+  // to avoid interfere with other tests.
+  DefaultValue<std::unique_ptr<Buzz>>::Clear();
+```
+
+To customize the default action for a particular method of a specific mock
+object, use [`ON_CALL`](reference/mocking.md#ON_CALL). `ON_CALL` has a similar
+syntax to `EXPECT_CALL`, but it is used for setting default behaviors when you
+do not require that the mock method is called. See
+[Knowing When to Expect](gmock_cook_book.md#UseOnCall) for a more detailed
+discussion.
+
+## Setting Expectations {#ExpectCall}
+
+See [`EXPECT_CALL`](reference/mocking.md#EXPECT_CALL) in the Mocking Reference.
+
+## Matchers {#MatcherList}
+
+See the [Matchers Reference](reference/matchers.md).
+
+## Actions {#ActionList}
+
+See the [Actions Reference](reference/actions.md).
+
+## Cardinalities {#CardinalityList}
+
+See the [`Times` clause](reference/mocking.md#EXPECT_CALL.Times) of
+`EXPECT_CALL` in the Mocking Reference.
+
+## Expectation Order
+
+By default, expectations can be matched in *any* order. If some or all
+expectations must be matched in a given order, you can use the
+[`After` clause](reference/mocking.md#EXPECT_CALL.After) or
+[`InSequence` clause](reference/mocking.md#EXPECT_CALL.InSequence) of
+`EXPECT_CALL`, or use an [`InSequence` object](reference/mocking.md#InSequence).
+
+## Verifying and Resetting a Mock
+
+gMock will verify the expectations on a mock object when it is destructed, or
+you can do it earlier:
+
+```cpp
+using ::testing::Mock;
+...
+// Verifies and removes the expectations on mock_obj;
+// returns true if and only if successful.
+Mock::VerifyAndClearExpectations(&mock_obj);
+...
+// Verifies and removes the expectations on mock_obj;
+// also removes the default actions set by ON_CALL();
+// returns true if and only if successful.
+Mock::VerifyAndClear(&mock_obj);
+```
+
+Do not set new expectations after verifying and clearing a mock after its use.
+Setting expectations after code that exercises the mock has undefined behavior.
+See [Using Mocks in Tests](gmock_for_dummies.md#using-mocks-in-tests) for more
+information.
+
+You can also tell gMock that a mock object can be leaked and doesn't need to be
+verified:
+
+```cpp
+Mock::AllowLeak(&mock_obj);
+```
+
+## Mock Classes
+
+gMock defines a convenient mock class template
+
+```cpp
+class MockFunction<R(A1, ..., An)> {
+ public:
+  MOCK_METHOD(R, Call, (A1, ..., An));
+};
+```
+
+See this [recipe](gmock_cook_book.md#using-check-points) for one application of
+it.
+
+## Flags
+
+| Flag                           | Description                               |
+| :----------------------------- | :---------------------------------------- |
+| `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as failures. |
+| `--gmock_verbose=LEVEL` | Sets the default verbosity level (`info`, `warning`, or `error`) of Google Mock messages. |

test/gtest-1.11.0/docs/gmock_faq.md

@@ -0,0 +1,390 @@
+# Legacy gMock FAQ
+
+### When I call a method on my mock object, the method for the real object is invoked instead. What's the problem?
+
+In order for a method to be mocked, it must be *virtual*, unless you use the
+[high-perf dependency injection technique](gmock_cook_book.md#MockingNonVirtualMethods).
+
+### Can I mock a variadic function?
+
+You cannot mock a variadic function (i.e. a function taking ellipsis (`...`)
+arguments) directly in gMock.
+
+The problem is that in general, there is *no way* for a mock object to know how
+many arguments are passed to the variadic method, and what the arguments' types
+are. Only the *author of the base class* knows the protocol, and we cannot look
+into his or her head.
+
+Therefore, to mock such a function, the *user* must teach the mock object how to
+figure out the number of arguments and their types. One way to do it is to
+provide overloaded versions of the function.
+
+Ellipsis arguments are inherited from C and not really a C++ feature. They are
+unsafe to use and don't work with arguments that have constructors or
+destructors. Therefore we recommend to avoid them in C++ as much as possible.
+
+### MSVC gives me warning C4301 or C4373 when I define a mock method with a const parameter. Why?
+
+If you compile this using Microsoft Visual C++ 2005 SP1:
+
+```cpp
+class Foo {
+  ...
+  virtual void Bar(const int i) = 0;
+};
+
+class MockFoo : public Foo {
+  ...
+  MOCK_METHOD(void, Bar, (const int i), (override));
+};
+```
+
+You may get the following warning:
+
+```shell
+warning C4301: 'MockFoo::Bar': overriding virtual function only differs from 'Foo::Bar' by const/volatile qualifier
+```
+
+This is a MSVC bug. The same code compiles fine with gcc, for example. If you
+use Visual C++ 2008 SP1, you would get the warning:
+
+```shell
+warning C4373: 'MockFoo::Bar': virtual function overrides 'Foo::Bar', previous versions of the compiler did not override when parameters only differed by const/volatile qualifiers
+```
+
+In C++, if you *declare* a function with a `const` parameter, the `const`
+modifier is ignored. Therefore, the `Foo` base class above is equivalent to:
+
+```cpp
+class Foo {
+  ...
+  virtual void Bar(int i) = 0;  // int or const int?  Makes no difference.
+};
+```
+
+In fact, you can *declare* `Bar()` with an `int` parameter, and define it with a
+`const int` parameter. The compiler will still match them up.
+
+Since making a parameter `const` is meaningless in the method declaration, we
+recommend to remove it in both `Foo` and `MockFoo`. That should workaround the
+VC bug.
+
+Note that we are talking about the *top-level* `const` modifier here. If the
+function parameter is passed by pointer or reference, declaring the pointee or
+referee as `const` is still meaningful. For example, the following two
+declarations are *not* equivalent:
+
+```cpp
+void Bar(int* p);         // Neither p nor *p is const.
+void Bar(const int* p);  // p is not const, but *p is.
+```
+
+### I can't figure out why gMock thinks my expectations are not satisfied. What should I do?
+
+You might want to run your test with `--gmock_verbose=info`. This flag lets
+gMock print a trace of every mock function call it receives. By studying the
+trace, you'll gain insights on why the expectations you set are not met.
+
+If you see the message "The mock function has no default action set, and its
+return type has no default value set.", then try
+[adding a default action](gmock_cheat_sheet.md#OnCall). Due to a known issue,
+unexpected calls on mocks without default actions don't print out a detailed
+comparison between the actual arguments and the expected arguments.
+
+### My program crashed and `ScopedMockLog` spit out tons of messages. Is it a gMock bug?
+
+gMock and `ScopedMockLog` are likely doing the right thing here.
+
+When a test crashes, the failure signal handler will try to log a lot of
+information (the stack trace, and the address map, for example). The messages
+are compounded if you have many threads with depth stacks. When `ScopedMockLog`
+intercepts these messages and finds that they don't match any expectations, it
+prints an error for each of them.
+
+You can learn to ignore the errors, or you can rewrite your expectations to make
+your test more robust, for example, by adding something like:
+
+```cpp
+using ::testing::AnyNumber;
+using ::testing::Not;
+...
+  // Ignores any log not done by us.
+  EXPECT_CALL(log, Log(_, Not(EndsWith("/my_file.cc")), _))
+      .Times(AnyNumber());
+```
+
+### How can I assert that a function is NEVER called?
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(foo, Bar(_))
+      .Times(0);
+```
+
+### I have a failed test where gMock tells me TWICE that a particular expectation is not satisfied. Isn't this redundant?
+
+When gMock detects a failure, it prints relevant information (the mock function
+arguments, the state of relevant expectations, and etc) to help the user debug.
+If another failure is detected, gMock will do the same, including printing the
+state of relevant expectations.
+
+Sometimes an expectation's state didn't change between two failures, and you'll
+see the same description of the state twice. They are however *not* redundant,
+as they refer to *different points in time*. The fact they are the same *is*
+interesting information.
+
+### I get a heapcheck failure when using a mock object, but using a real object is fine. What can be wrong?
+
+Does the class (hopefully a pure interface) you are mocking have a virtual
+destructor?
+
+Whenever you derive from a base class, make sure its destructor is virtual.
+Otherwise Bad Things will happen. Consider the following code:
+
+```cpp
+class Base {
+ public:
+  // Not virtual, but should be.
+  ~Base() { ... }
+  ...
+};
+
+class Derived : public Base {
+ public:
+  ...
+ private:
+  std::string value_;
+};
+
+...
+  Base* p = new Derived;
+  ...
+  delete p;  // Surprise! ~Base() will be called, but ~Derived() will not
+                 // - value_ is leaked.
+```
+
+By changing `~Base()` to virtual, `~Derived()` will be correctly called when
+`delete p` is executed, and the heap checker will be happy.
+
+### The "newer expectations override older ones" rule makes writing expectations awkward. Why does gMock do that?
+
+When people complain about this, often they are referring to code like:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.  However, I have to write the expectations in the
+  // reverse order.  This sucks big time!!!
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(2))
+      .RetiresOnSaturation();
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(1))
+      .RetiresOnSaturation();
+```
+
+The problem, is that they didn't pick the **best** way to express the test's
+intent.
+
+By default, expectations don't have to be matched in *any* particular order. If
+you want them to match in a certain order, you need to be explicit. This is
+gMock's (and jMock's) fundamental philosophy: it's easy to accidentally
+over-specify your tests, and we want to make it harder to do so.
+
+There are two better ways to write the test spec. You could either put the
+expectations in sequence:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.  Using a sequence, we can write the expectations
+  // in their natural order.
+  {
+    InSequence s;
+    EXPECT_CALL(foo, Bar())
+        .WillOnce(Return(1))
+        .RetiresOnSaturation();
+    EXPECT_CALL(foo, Bar())
+        .WillOnce(Return(2))
+        .RetiresOnSaturation();
+  }
+```
+
+or you can put the sequence of actions in the same expectation:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(1))
+      .WillOnce(Return(2))
+      .RetiresOnSaturation();
+```
+
+Back to the original questions: why does gMock search the expectations (and
+`ON_CALL`s) from back to front? Because this allows a user to set up a mock's
+behavior for the common case early (e.g. in the mock's constructor or the test
+fixture's set-up phase) and customize it with more specific rules later. If
+gMock searches from front to back, this very useful pattern won't be possible.
+
+### gMock prints a warning when a function without EXPECT_CALL is called, even if I have set its behavior using ON_CALL. Would it be reasonable not to show the warning in this case?
+
+When choosing between being neat and being safe, we lean toward the latter. So
+the answer is that we think it's better to show the warning.
+
+Often people write `ON_CALL`s in the mock object's constructor or `SetUp()`, as
+the default behavior rarely changes from test to test. Then in the test body
+they set the expectations, which are often different for each test. Having an
+`ON_CALL` in the set-up part of a test doesn't mean that the calls are expected.
+If there's no `EXPECT_CALL` and the method is called, it's possibly an error. If
+we quietly let the call go through without notifying the user, bugs may creep in
+unnoticed.
+
+If, however, you are sure that the calls are OK, you can write
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(foo, Bar(_))
+      .WillRepeatedly(...);
+```
+
+instead of
+
+```cpp
+using ::testing::_;
+...
+  ON_CALL(foo, Bar(_))
+      .WillByDefault(...);
+```
+
+This tells gMock that you do expect the calls and no warning should be printed.
+
+Also, you can control the verbosity by specifying `--gmock_verbose=error`. Other
+values are `info` and `warning`. If you find the output too noisy when
+debugging, just choose a less verbose level.
+
+### How can I delete the mock function's argument in an action?
+
+If your mock function takes a pointer argument and you want to delete that
+argument, you can use testing::DeleteArg<N>() to delete the N'th (zero-indexed)
+argument:
+
+```cpp
+using ::testing::_;
+  ...
+  MOCK_METHOD(void, Bar, (X* x, const Y& y));
+  ...
+  EXPECT_CALL(mock_foo_, Bar(_, _))
+      .WillOnce(testing::DeleteArg<0>()));
+```
+
+### How can I perform an arbitrary action on a mock function's argument?
+
+If you find yourself needing to perform some action that's not supported by
+gMock directly, remember that you can define your own actions using
+[`MakeAction()`](#NewMonoActions) or
+[`MakePolymorphicAction()`](#NewPolyActions), or you can write a stub function
+and invoke it using [`Invoke()`](#FunctionsAsActions).
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+  ...
+  MOCK_METHOD(void, Bar, (X* p));
+  ...
+  EXPECT_CALL(mock_foo_, Bar(_))
+      .WillOnce(Invoke(MyAction(...)));
+```
+
+### My code calls a static/global function. Can I mock it?
+
+You can, but you need to make some changes.
+
+In general, if you find yourself needing to mock a static function, it's a sign
+that your modules are too tightly coupled (and less flexible, less reusable,
+less testable, etc). You are probably better off defining a small interface and
+call the function through that interface, which then can be easily mocked. It's
+a bit of work initially, but usually pays for itself quickly.
+
+This Google Testing Blog
+[post](https://testing.googleblog.com/2008/06/defeat-static-cling.html) says it
+excellently. Check it out.
+
+### My mock object needs to do complex stuff. It's a lot of pain to specify the actions. gMock sucks!
+
+I know it's not a question, but you get an answer for free any way. :-)
+
+With gMock, you can create mocks in C++ easily. And people might be tempted to
+use them everywhere. Sometimes they work great, and sometimes you may find them,
+well, a pain to use. So, what's wrong in the latter case?
+
+When you write a test without using mocks, you exercise the code and assert that
+it returns the correct value or that the system is in an expected state. This is
+sometimes called "state-based testing".
+
+Mocks are great for what some call "interaction-based" testing: instead of
+checking the system state at the very end, mock objects verify that they are
+invoked the right way and report an error as soon as it arises, giving you a
+handle on the precise context in which the error was triggered. This is often
+more effective and economical to do than state-based testing.
+
+If you are doing state-based testing and using a test double just to simulate
+the real object, you are probably better off using a fake. Using a mock in this
+case causes pain, as it's not a strong point for mocks to perform complex
+actions. If you experience this and think that mocks suck, you are just not
+using the right tool for your problem. Or, you might be trying to solve the
+wrong problem. :-)
+
+### I got a warning "Uninteresting function call encountered - default action taken.." Should I panic?
+
+By all means, NO! It's just an FYI. :-)
+
+What it means is that you have a mock function, you haven't set any expectations
+on it (by gMock's rule this means that you are not interested in calls to this
+function and therefore it can be called any number of times), and it is called.
+That's OK - you didn't say it's not OK to call the function!
+
+What if you actually meant to disallow this function to be called, but forgot to
+write `EXPECT_CALL(foo, Bar()).Times(0)`? While one can argue that it's the
+user's fault, gMock tries to be nice and prints you a note.
+
+So, when you see the message and believe that there shouldn't be any
+uninteresting calls, you should investigate what's going on. To make your life
+easier, gMock dumps the stack trace when an uninteresting call is encountered.
+From that you can figure out which mock function it is, and how it is called.
+
+### I want to define a custom action. Should I use Invoke() or implement the ActionInterface interface?
+
+Either way is fine - you want to choose the one that's more convenient for your
+circumstance.
+
+Usually, if your action is for a particular function type, defining it using
+`Invoke()` should be easier; if your action can be used in functions of
+different types (e.g. if you are defining `Return(*value*)`),
+`MakePolymorphicAction()` is easiest. Sometimes you want precise control on what
+types of functions the action can be used in, and implementing `ActionInterface`
+is the way to go here. See the implementation of `Return()` in
+`testing/base/public/gmock-actions.h` for an example.
+
+### I use SetArgPointee() in WillOnce(), but gcc complains about "conflicting return type specified". What does it mean?
+
+You got this error as gMock has no idea what value it should return when the
+mock method is called. `SetArgPointee()` says what the side effect is, but
+doesn't say what the return value should be. You need `DoAll()` to chain a
+`SetArgPointee()` with a `Return()` that provides a value appropriate to the API
+being mocked.
+
+See this [recipe](gmock_cook_book.md#mocking-side-effects) for more details and
+an example.
+
+### I have a huge mock class, and Microsoft Visual C++ runs out of memory when compiling it. What can I do?
+
+We've noticed that when the `/clr` compiler flag is used, Visual C++ uses 5~6
+times as much memory when compiling a mock class. We suggest to avoid `/clr`
+when compiling native C++ mocks.

test/gtest-1.11.0/docs/gmock_for_dummies.md

@@ -0,0 +1,700 @@
+# gMock for Dummies
+
+## What Is gMock?
+
+When you write a prototype or test, often it's not feasible or wise to rely on
+real objects entirely. A **mock object** implements the same interface as a real
+object (so it can be used as one), but lets you specify at run time how it will
+be used and what it should do (which methods will be called? in which order? how
+many times? with what arguments? what will they return? etc).
+
+It is easy to confuse the term *fake objects* with mock objects. Fakes and mocks
+actually mean very different things in the Test-Driven Development (TDD)
+community:
+
+*   **Fake** objects have working implementations, but usually take some
+    shortcut (perhaps to make the operations less expensive), which makes them
+    not suitable for production. An in-memory file system would be an example of
+    a fake.
+*   **Mocks** are objects pre-programmed with *expectations*, which form a
+    specification of the calls they are expected to receive.
+
+If all this seems too abstract for you, don't worry - the most important thing
+to remember is that a mock allows you to check the *interaction* between itself
+and code that uses it. The difference between fakes and mocks shall become much
+clearer once you start to use mocks.
+
+**gMock** is a library (sometimes we also call it a "framework" to make it sound
+cool) for creating mock classes and using them. It does to C++ what
+jMock/EasyMock does to Java (well, more or less).
+
+When using gMock,
+
+1.  first, you use some simple macros to describe the interface you want to
+    mock, and they will expand to the implementation of your mock class;
+2.  next, you create some mock objects and specify its expectations and behavior
+    using an intuitive syntax;
+3.  then you exercise code that uses the mock objects. gMock will catch any
+    violation to the expectations as soon as it arises.
+
+## Why gMock?
+
+While mock objects help you remove unnecessary dependencies in tests and make
+them fast and reliable, using mocks manually in C++ is *hard*:
+
+*   Someone has to implement the mocks. The job is usually tedious and
+    error-prone. No wonder people go great distance to avoid it.
+*   The quality of those manually written mocks is a bit, uh, unpredictable. You
+    may see some really polished ones, but you may also see some that were
+    hacked up in a hurry and have all sorts of ad hoc restrictions.
+*   The knowledge you gained from using one mock doesn't transfer to the next
+    one.
+
+In contrast, Java and Python programmers have some fine mock frameworks (jMock,
+EasyMock, etc), which automate the creation of mocks. As a result, mocking is a
+proven effective technique and widely adopted practice in those communities.
+Having the right tool absolutely makes the difference.
+
+gMock was built to help C++ programmers. It was inspired by jMock and EasyMock,
+but designed with C++'s specifics in mind. It is your friend if any of the
+following problems is bothering you:
+
+*   You are stuck with a sub-optimal design and wish you had done more
+    prototyping before it was too late, but prototyping in C++ is by no means
+    "rapid".
+*   Your tests are slow as they depend on too many libraries or use expensive
+    resources (e.g. a database).
+*   Your tests are brittle as some resources they use are unreliable (e.g. the
+    network).
+*   You want to test how your code handles a failure (e.g. a file checksum
+    error), but it's not easy to cause one.
+*   You need to make sure that your module interacts with other modules in the
+    right way, but it's hard to observe the interaction; therefore you resort to
+    observing the side effects at the end of the action, but it's awkward at
+    best.
+*   You want to "mock out" your dependencies, except that they don't have mock
+    implementations yet; and, frankly, you aren't thrilled by some of those
+    hand-written mocks.
+
+We encourage you to use gMock as
+
+*   a *design* tool, for it lets you experiment with your interface design early
+    and often. More iterations lead to better designs!
+*   a *testing* tool to cut your tests' outbound dependencies and probe the
+    interaction between your module and its collaborators.
+
+## Getting Started
+
+gMock is bundled with googletest.
+
+## A Case for Mock Turtles
+
+Let's look at an example. Suppose you are developing a graphics program that
+relies on a [LOGO](http://en.wikipedia.org/wiki/Logo_programming_language)-like
+API for drawing. How would you test that it does the right thing? Well, you can
+run it and compare the screen with a golden screen snapshot, but let's admit it:
+tests like this are expensive to run and fragile (What if you just upgraded to a
+shiny new graphics card that has better anti-aliasing? Suddenly you have to
+update all your golden images.). It would be too painful if all your tests are
+like this. Fortunately, you learned about
+[Dependency Injection](http://en.wikipedia.org/wiki/Dependency_injection) and know the right thing
+to do: instead of having your application talk to the system API directly, wrap
+the API in an interface (say, `Turtle`) and code to that interface:
+
+```cpp
+class Turtle {
+  ...
+  virtual ~Turtle() {}
+  virtual void PenUp() = 0;
+  virtual void PenDown() = 0;
+  virtual void Forward(int distance) = 0;
+  virtual void Turn(int degrees) = 0;
+  virtual void GoTo(int x, int y) = 0;
+  virtual int GetX() const = 0;
+  virtual int GetY() const = 0;
+};
+```
+
+(Note that the destructor of `Turtle` **must** be virtual, as is the case for
+**all** classes you intend to inherit from - otherwise the destructor of the
+derived class will not be called when you delete an object through a base
+pointer, and you'll get corrupted program states like memory leaks.)
+
+You can control whether the turtle's movement will leave a trace using `PenUp()`
+and `PenDown()`, and control its movement using `Forward()`, `Turn()`, and
+`GoTo()`. Finally, `GetX()` and `GetY()` tell you the current position of the
+turtle.
+
+Your program will normally use a real implementation of this interface. In
+tests, you can use a mock implementation instead. This allows you to easily
+check what drawing primitives your program is calling, with what arguments, and
+in which order. Tests written this way are much more robust (they won't break
+because your new machine does anti-aliasing differently), easier to read and
+maintain (the intent of a test is expressed in the code, not in some binary
+images), and run *much, much faster*.
+
+## Writing the Mock Class
+
+If you are lucky, the mocks you need to use have already been implemented by
+some nice people. If, however, you find yourself in the position to write a mock
+class, relax - gMock turns this task into a fun game! (Well, almost.)
+
+### How to Define It
+
+Using the `Turtle` interface as example, here are the simple steps you need to
+follow:
+
+*   Derive a class `MockTurtle` from `Turtle`.
+*   Take a *virtual* function of `Turtle` (while it's possible to
+    [mock non-virtual methods using templates](gmock_cook_book.md#MockingNonVirtualMethods),
+    it's much more involved).
+*   In the `public:` section of the child class, write `MOCK_METHOD();`
+*   Now comes the fun part: you take the function signature, cut-and-paste it
+    into the macro, and add two commas - one between the return type and the
+    name, another between the name and the argument list.
+*   If you're mocking a const method, add a 4th parameter containing `(const)`
+    (the parentheses are required).
+*   Since you're overriding a virtual method, we suggest adding the `override`
+    keyword. For const methods the 4th parameter becomes `(const, override)`,
+    for non-const methods just `(override)`. This isn't mandatory.
+*   Repeat until all virtual functions you want to mock are done. (It goes
+    without saying that *all* pure virtual methods in your abstract class must
+    be either mocked or overridden.)
+
+After the process, you should have something like:
+
+```cpp
+#include "gmock/gmock.h"  // Brings in gMock.
+
+class MockTurtle : public Turtle {
+ public:
+  ...
+  MOCK_METHOD(void, PenUp, (), (override));
+  MOCK_METHOD(void, PenDown, (), (override));
+  MOCK_METHOD(void, Forward, (int distance), (override));
+  MOCK_METHOD(void, Turn, (int degrees), (override));
+  MOCK_METHOD(void, GoTo, (int x, int y), (override));
+  MOCK_METHOD(int, GetX, (), (const, override));
+  MOCK_METHOD(int, GetY, (), (const, override));
+};
+```
+
+You don't need to define these mock methods somewhere else - the `MOCK_METHOD`
+macro will generate the definitions for you. It's that simple!
+
+### Where to Put It
+
+When you define a mock class, you need to decide where to put its definition.
+Some people put it in a `_test.cc`. This is fine when the interface being mocked
+(say, `Foo`) is owned by the same person or team. Otherwise, when the owner of
+`Foo` changes it, your test could break. (You can't really expect `Foo`'s
+maintainer to fix every test that uses `Foo`, can you?)
+
+So, the rule of thumb is: if you need to mock `Foo` and it's owned by others,
+define the mock class in `Foo`'s package (better, in a `testing` sub-package
+such that you can clearly separate production code and testing utilities), put
+it in a `.h` and a `cc_library`. Then everyone can reference them from their
+tests. If `Foo` ever changes, there is only one copy of `MockFoo` to change, and
+only tests that depend on the changed methods need to be fixed.
+
+Another way to do it: you can introduce a thin layer `FooAdaptor` on top of
+`Foo` and code to this new interface. Since you own `FooAdaptor`, you can absorb
+changes in `Foo` much more easily. While this is more work initially, carefully
+choosing the adaptor interface can make your code easier to write and more
+readable (a net win in the long run), as you can choose `FooAdaptor` to fit your
+specific domain much better than `Foo` does.
+
+## Using Mocks in Tests
+
+Once you have a mock class, using it is easy. The typical work flow is:
+
+1.  Import the gMock names from the `testing` namespace such that you can use
+    them unqualified (You only have to do it once per file). Remember that
+    namespaces are a good idea.
+2.  Create some mock objects.
+3.  Specify your expectations on them (How many times will a method be called?
+    With what arguments? What should it do? etc.).
+4.  Exercise some code that uses the mocks; optionally, check the result using
+    googletest assertions. If a mock method is called more than expected or with
+    wrong arguments, you'll get an error immediately.
+5.  When a mock is destructed, gMock will automatically check whether all
+    expectations on it have been satisfied.
+
+Here's an example:
+
+```cpp
+#include "path/to/mock-turtle.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using ::testing::AtLeast;                         // #1
+
+TEST(PainterTest, CanDrawSomething) {
+  MockTurtle turtle;                              // #2
+  EXPECT_CALL(turtle, PenDown())                  // #3
+      .Times(AtLeast(1));
+
+  Painter painter(&turtle);                       // #4
+
+  EXPECT_TRUE(painter.DrawCircle(0, 0, 10));      // #5
+}
+```
+
+As you might have guessed, this test checks that `PenDown()` is called at least
+once. If the `painter` object didn't call this method, your test will fail with
+a message like this:
+
+```text
+path/to/my_test.cc:119: Failure
+Actual function call count doesn't match this expectation:
+Actually: never called;
+Expected: called at least once.
+Stack trace:
+...
+```
+
+**Tip 1:** If you run the test from an Emacs buffer, you can hit `<Enter>` on
+the line number to jump right to the failed expectation.
+
+**Tip 2:** If your mock objects are never deleted, the final verification won't
+happen. Therefore it's a good idea to turn on the heap checker in your tests
+when you allocate mocks on the heap. You get that automatically if you use the
+`gtest_main` library already.
+
+**Important note:** gMock requires expectations to be set **before** the mock
+functions are called, otherwise the behavior is **undefined**. Do not alternate
+between calls to `EXPECT_CALL()` and calls to the mock functions, and do not set
+any expectations on a mock after passing the mock to an API.
+
+This means `EXPECT_CALL()` should be read as expecting that a call will occur
+*in the future*, not that a call has occurred. Why does gMock work like that?
+Well, specifying the expectation beforehand allows gMock to report a violation
+as soon as it rises, when the context (stack trace, etc) is still available.
+This makes debugging much easier.
+
+Admittedly, this test is contrived and doesn't do much. You can easily achieve
+the same effect without using gMock. However, as we shall reveal soon, gMock
+allows you to do *so much more* with the mocks.
+
+## Setting Expectations
+
+The key to using a mock object successfully is to set the *right expectations*
+on it. If you set the expectations too strict, your test will fail as the result
+of unrelated changes. If you set them too loose, bugs can slip through. You want
+to do it just right such that your test can catch exactly the kind of bugs you
+intend it to catch. gMock provides the necessary means for you to do it "just
+right."
+
+### General Syntax
+
+In gMock we use the `EXPECT_CALL()` macro to set an expectation on a mock
+method. The general syntax is:
+
+```cpp
+EXPECT_CALL(mock_object, method(matchers))
+    .Times(cardinality)
+    .WillOnce(action)
+    .WillRepeatedly(action);
+```
+
+The macro has two arguments: first the mock object, and then the method and its
+arguments. Note that the two are separated by a comma (`,`), not a period (`.`).
+(Why using a comma? The answer is that it was necessary for technical reasons.)
+If the method is not overloaded, the macro can also be called without matchers:
+
+```cpp
+EXPECT_CALL(mock_object, non-overloaded-method)
+    .Times(cardinality)
+    .WillOnce(action)
+    .WillRepeatedly(action);
+```
+
+This syntax allows the test writer to specify "called with any arguments"
+without explicitly specifying the number or types of arguments. To avoid
+unintended ambiguity, this syntax may only be used for methods that are not
+overloaded.
+
+Either form of the macro can be followed by some optional *clauses* that provide
+more information about the expectation. We'll discuss how each clause works in
+the coming sections.
+
+This syntax is designed to make an expectation read like English. For example,
+you can probably guess that
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetX())
+    .Times(5)
+    .WillOnce(Return(100))
+    .WillOnce(Return(150))
+    .WillRepeatedly(Return(200));
+```
+
+says that the `turtle` object's `GetX()` method will be called five times, it
+will return 100 the first time, 150 the second time, and then 200 every time.
+Some people like to call this style of syntax a Domain-Specific Language (DSL).
+
+{: .callout .note}
+**Note:** Why do we use a macro to do this? Well it serves two purposes: first
+it makes expectations easily identifiable (either by `grep` or by a human
+reader), and second it allows gMock to include the source file location of a
+failed expectation in messages, making debugging easier.
+
+### Matchers: What Arguments Do We Expect?
+
+When a mock function takes arguments, we may specify what arguments we are
+expecting, for example:
+
+```cpp
+// Expects the turtle to move forward by 100 units.
+EXPECT_CALL(turtle, Forward(100));
+```
+
+Oftentimes you do not want to be too specific. Remember that talk about tests
+being too rigid? Over specification leads to brittle tests and obscures the
+intent of tests. Therefore we encourage you to specify only what's necessary—no
+more, no less. If you aren't interested in the value of an argument, write `_`
+as the argument, which means "anything goes":
+
+```cpp
+using ::testing::_;
+...
+// Expects that the turtle jumps to somewhere on the x=50 line.
+EXPECT_CALL(turtle, GoTo(50, _));
+```
+
+`_` is an instance of what we call **matchers**. A matcher is like a predicate
+and can test whether an argument is what we'd expect. You can use a matcher
+inside `EXPECT_CALL()` wherever a function argument is expected. `_` is a
+convenient way of saying "any value".
+
+In the above examples, `100` and `50` are also matchers; implicitly, they are
+the same as `Eq(100)` and `Eq(50)`, which specify that the argument must be
+equal (using `operator==`) to the matcher argument. There are many
+[built-in matchers](reference/matchers.md) for common types (as well as
+[custom matchers](gmock_cook_book.md#NewMatchers)); for example:
+
+```cpp
+using ::testing::Ge;
+...
+// Expects the turtle moves forward by at least 100.
+EXPECT_CALL(turtle, Forward(Ge(100)));
+```
+
+If you don't care about *any* arguments, rather than specify `_` for each of
+them you may instead omit the parameter list:
+
+```cpp
+// Expects the turtle to move forward.
+EXPECT_CALL(turtle, Forward);
+// Expects the turtle to jump somewhere.
+EXPECT_CALL(turtle, GoTo);
+```
+
+This works for all non-overloaded methods; if a method is overloaded, you need
+to help gMock resolve which overload is expected by specifying the number of
+arguments and possibly also the
+[types of the arguments](gmock_cook_book.md#SelectOverload).
+
+### Cardinalities: How Many Times Will It Be Called?
+
+The first clause we can specify following an `EXPECT_CALL()` is `Times()`. We
+call its argument a **cardinality** as it tells *how many times* the call should
+occur. It allows us to repeat an expectation many times without actually writing
+it as many times. More importantly, a cardinality can be "fuzzy", just like a
+matcher can be. This allows a user to express the intent of a test exactly.
+
+An interesting special case is when we say `Times(0)`. You may have guessed - it
+means that the function shouldn't be called with the given arguments at all, and
+gMock will report a googletest failure whenever the function is (wrongfully)
+called.
+
+We've seen `AtLeast(n)` as an example of fuzzy cardinalities earlier. For the
+list of built-in cardinalities you can use, see
+[here](gmock_cheat_sheet.md#CardinalityList).
+
+The `Times()` clause can be omitted. **If you omit `Times()`, gMock will infer
+the cardinality for you.** The rules are easy to remember:
+
+*   If **neither** `WillOnce()` **nor** `WillRepeatedly()` is in the
+    `EXPECT_CALL()`, the inferred cardinality is `Times(1)`.
+*   If there are *n* `WillOnce()`'s but **no** `WillRepeatedly()`, where *n* >=
+    1, the cardinality is `Times(n)`.
+*   If there are *n* `WillOnce()`'s and **one** `WillRepeatedly()`, where *n* >=
+    0, the cardinality is `Times(AtLeast(n))`.
+
+**Quick quiz:** what do you think will happen if a function is expected to be
+called twice but actually called four times?
+
+### Actions: What Should It Do?
+
+Remember that a mock object doesn't really have a working implementation? We as
+users have to tell it what to do when a method is invoked. This is easy in
+gMock.
+
+First, if the return type of a mock function is a built-in type or a pointer,
+the function has a **default action** (a `void` function will just return, a
+`bool` function will return `false`, and other functions will return 0). In
+addition, in C++ 11 and above, a mock function whose return type is
+default-constructible (i.e. has a default constructor) has a default action of
+returning a default-constructed value. If you don't say anything, this behavior
+will be used.
+
+Second, if a mock function doesn't have a default action, or the default action
+doesn't suit you, you can specify the action to be taken each time the
+expectation matches using a series of `WillOnce()` clauses followed by an
+optional `WillRepeatedly()`. For example,
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetX())
+     .WillOnce(Return(100))
+     .WillOnce(Return(200))
+     .WillOnce(Return(300));
+```
+
+says that `turtle.GetX()` will be called *exactly three times* (gMock inferred
+this from how many `WillOnce()` clauses we've written, since we didn't
+explicitly write `Times()`), and will return 100, 200, and 300 respectively.
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetY())
+     .WillOnce(Return(100))
+     .WillOnce(Return(200))
+     .WillRepeatedly(Return(300));
+```
+
+says that `turtle.GetY()` will be called *at least twice* (gMock knows this as
+we've written two `WillOnce()` clauses and a `WillRepeatedly()` while having no
+explicit `Times()`), will return 100 and 200 respectively the first two times,
+and 300 from the third time on.
+
+Of course, if you explicitly write a `Times()`, gMock will not try to infer the
+cardinality itself. What if the number you specified is larger than there are
+`WillOnce()` clauses? Well, after all `WillOnce()`s are used up, gMock will do
+the *default* action for the function every time (unless, of course, you have a
+`WillRepeatedly()`.).
+
+What can we do inside `WillOnce()` besides `Return()`? You can return a
+reference using `ReturnRef(*variable*)`, or invoke a pre-defined function, among
+[others](gmock_cook_book.md#using-actions).
+
+**Important note:** The `EXPECT_CALL()` statement evaluates the action clause
+only once, even though the action may be performed many times. Therefore you
+must be careful about side effects. The following may not do what you want:
+
+```cpp
+using ::testing::Return;
+...
+int n = 100;
+EXPECT_CALL(turtle, GetX())
+    .Times(4)
+    .WillRepeatedly(Return(n++));
+```
+
+Instead of returning 100, 101, 102, ..., consecutively, this mock function will
+always return 100 as `n++` is only evaluated once. Similarly, `Return(new Foo)`
+will create a new `Foo` object when the `EXPECT_CALL()` is executed, and will
+return the same pointer every time. If you want the side effect to happen every
+time, you need to define a custom action, which we'll teach in the
+[cook book](gmock_cook_book.md).
+
+Time for another quiz! What do you think the following means?
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetY())
+    .Times(4)
+    .WillOnce(Return(100));
+```
+
+Obviously `turtle.GetY()` is expected to be called four times. But if you think
+it will return 100 every time, think twice! Remember that one `WillOnce()`
+clause will be consumed each time the function is invoked and the default action
+will be taken afterwards. So the right answer is that `turtle.GetY()` will
+return 100 the first time, but **return 0 from the second time on**, as
+returning 0 is the default action for `int` functions.
+
+### Using Multiple Expectations {#MultiExpectations}
+
+So far we've only shown examples where you have a single expectation. More
+realistically, you'll specify expectations on multiple mock methods which may be
+from multiple mock objects.
+
+By default, when a mock method is invoked, gMock will search the expectations in
+the **reverse order** they are defined, and stop when an active expectation that
+matches the arguments is found (you can think of it as "newer rules override
+older ones."). If the matching expectation cannot take any more calls, you will
+get an upper-bound-violated failure. Here's an example:
+
+```cpp
+using ::testing::_;
+...
+EXPECT_CALL(turtle, Forward(_));  // #1
+EXPECT_CALL(turtle, Forward(10))  // #2
+    .Times(2);
+```
+
+If `Forward(10)` is called three times in a row, the third time it will be an
+error, as the last matching expectation (#2) has been saturated. If, however,
+the third `Forward(10)` call is replaced by `Forward(20)`, then it would be OK,
+as now #1 will be the matching expectation.
+
+{: .callout .note}
+**Note:** Why does gMock search for a match in the *reverse* order of the
+expectations? The reason is that this allows a user to set up the default
+expectations in a mock object's constructor or the test fixture's set-up phase
+and then customize the mock by writing more specific expectations in the test
+body. So, if you have two expectations on the same method, you want to put the
+one with more specific matchers **after** the other, or the more specific rule
+would be shadowed by the more general one that comes after it.
+
+{: .callout .tip}
+**Tip:** It is very common to start with a catch-all expectation for a method
+and `Times(AnyNumber())` (omitting arguments, or with `_` for all arguments, if
+overloaded). This makes any calls to the method expected. This is not necessary
+for methods that are not mentioned at all (these are "uninteresting"), but is
+useful for methods that have some expectations, but for which other calls are
+ok. See
+[Understanding Uninteresting vs Unexpected Calls](gmock_cook_book.md#uninteresting-vs-unexpected).
+
+### Ordered vs Unordered Calls {#OrderedCalls}
+
+By default, an expectation can match a call even though an earlier expectation
+hasn't been satisfied. In other words, the calls don't have to occur in the
+order the expectations are specified.
+
+Sometimes, you may want all the expected calls to occur in a strict order. To
+say this in gMock is easy:
+
+```cpp
+using ::testing::InSequence;
+...
+TEST(FooTest, DrawsLineSegment) {
+  ...
+  {
+    InSequence seq;
+
+    EXPECT_CALL(turtle, PenDown());
+    EXPECT_CALL(turtle, Forward(100));
+    EXPECT_CALL(turtle, PenUp());
+  }
+  Foo();
+}
+```
+
+By creating an object of type `InSequence`, all expectations in its scope are
+put into a *sequence* and have to occur *sequentially*. Since we are just
+relying on the constructor and destructor of this object to do the actual work,
+its name is really irrelevant.
+
+In this example, we test that `Foo()` calls the three expected functions in the
+order as written. If a call is made out-of-order, it will be an error.
+
+(What if you care about the relative order of some of the calls, but not all of
+them? Can you specify an arbitrary partial order? The answer is ... yes! The
+details can be found [here](gmock_cook_book.md#OrderedCalls).)
+
+### All Expectations Are Sticky (Unless Said Otherwise) {#StickyExpectations}
+
+Now let's do a quick quiz to see how well you can use this mock stuff already.
+How would you test that the turtle is asked to go to the origin *exactly twice*
+(you want to ignore any other instructions it receives)?
+
+After you've come up with your answer, take a look at ours and compare notes
+(solve it yourself first - don't cheat!):
+
+```cpp
+using ::testing::_;
+using ::testing::AnyNumber;
+...
+EXPECT_CALL(turtle, GoTo(_, _))  // #1
+     .Times(AnyNumber());
+EXPECT_CALL(turtle, GoTo(0, 0))  // #2
+     .Times(2);
+```
+
+Suppose `turtle.GoTo(0, 0)` is called three times. In the third time, gMock will
+see that the arguments match expectation #2 (remember that we always pick the
+last matching expectation). Now, since we said that there should be only two
+such calls, gMock will report an error immediately. This is basically what we've
+told you in the [Using Multiple Expectations](#MultiExpectations) section above.
+
+This example shows that **expectations in gMock are "sticky" by default**, in
+the sense that they remain active even after we have reached their invocation
+upper bounds. This is an important rule to remember, as it affects the meaning
+of the spec, and is **different** to how it's done in many other mocking
+frameworks (Why'd we do that? Because we think our rule makes the common cases
+easier to express and understand.).
+
+Simple? Let's see if you've really understood it: what does the following code
+say?
+
+```cpp
+using ::testing::Return;
+...
+for (int i = n; i > 0; i--) {
+  EXPECT_CALL(turtle, GetX())
+      .WillOnce(Return(10*i));
+}
+```
+
+If you think it says that `turtle.GetX()` will be called `n` times and will
+return 10, 20, 30, ..., consecutively, think twice! The problem is that, as we
+said, expectations are sticky. So, the second time `turtle.GetX()` is called,
+the last (latest) `EXPECT_CALL()` statement will match, and will immediately
+lead to an "upper bound violated" error - this piece of code is not very useful!
+
+One correct way of saying that `turtle.GetX()` will return 10, 20, 30, ..., is
+to explicitly say that the expectations are *not* sticky. In other words, they
+should *retire* as soon as they are saturated:
+
+```cpp
+using ::testing::Return;
+...
+for (int i = n; i > 0; i--) {
+  EXPECT_CALL(turtle, GetX())
+      .WillOnce(Return(10*i))
+      .RetiresOnSaturation();
+}
+```
+
+And, there's a better way to do it: in this case, we expect the calls to occur
+in a specific order, and we line up the actions to match the order. Since the
+order is important here, we should make it explicit using a sequence:
+
+```cpp
+using ::testing::InSequence;
+using ::testing::Return;
+...
+{
+  InSequence s;
+
+  for (int i = 1; i <= n; i++) {
+    EXPECT_CALL(turtle, GetX())
+        .WillOnce(Return(10*i))
+        .RetiresOnSaturation();
+  }
+}
+```
+
+By the way, the other situation where an expectation may *not* be sticky is when
+it's in a sequence - as soon as another expectation that comes after it in the
+sequence has been used, it automatically retires (and will never be used to
+match any call).
+
+### Uninteresting Calls
+
+A mock object may have many methods, and not all of them are that interesting.
+For example, in some tests we may not care about how many times `GetX()` and
+`GetY()` get called.
+
+In gMock, if you are not interested in a method, just don't say anything about
+it. If a call to this method occurs, you'll see a warning in the test output,
+but it won't be a failure. This is called "naggy" behavior; to change, see
+[The Nice, the Strict, and the Naggy](gmock_cook_book.md#NiceStrictNaggy).

test/gtest-1.11.0/docs/index.md

@@ -0,0 +1,22 @@
+# GoogleTest User's Guide
+
+## Welcome to GoogleTest!
+
+GoogleTest is Google's C++ testing and mocking framework. This user's guide has
+the following contents:
+
+*   [GoogleTest Primer](primer.md) - Teaches you how to write simple tests using
+    GoogleTest. Read this first if you are new to GoogleTest.
+*   [GoogleTest Advanced](advanced.md) - Read this when you've finished the
+    Primer and want to utilize GoogleTest to its full potential.
+*   [GoogleTest Samples](samples.md) - Describes some GoogleTest samples.
+*   [GoogleTest FAQ](faq.md) - Have a question? Want some tips? Check here
+    first.
+*   [Mocking for Dummies](gmock_for_dummies.md) - Teaches you how to create mock
+    objects and use them in tests.
+*   [Mocking Cookbook](gmock_cook_book.md) - Includes tips and approaches to
+    common mocking use cases.
+*   [Mocking Cheat Sheet](gmock_cheat_sheet.md) - A handy reference for
+    matchers, actions, invariants, and more.
+*   [Mocking FAQ](gmock_faq.md) - Contains answers to some mocking-specific
+    questions.