llvm-mirror/unittests/ADT/RangeAdapterTest.cpp
Pete Cooper 37a409c394 Reapply "Add reverse(ContainerTy) range adapter."
This reverts commit r243567, which ultimately reapplies r243563.

The fix here was to use std::enable_if for overload resolution.  Thanks to David
Blaikie for lots of help on this, and for the extra tests!

Original commit message follows:

For cases where we needed a foreach loop in reverse over a container,
we had to do something like

 for (const GlobalValue *GV : make_range(TypeInfos.rbegin(),
                                         TypeInfos.rend())) {

This provides a convenience method which shortens this to

 for (const GlobalValue *GV : reverse(TypeInfos)) {

There are 2 versions of this, with a preference to the rbegin() version.

The first uses rbegin() and rend() to construct an iterator_range.

The second constructs an iterator_range from the begin() and end() methods
wrapped in std::reverse_iterator's.

Reviewed by David Blaikie.

llvm-svn: 243581
2015-07-29 22:19:09 +00:00

84 lines
2.4 KiB
C++

//===- RangeAdapterTest.cpp - Unit tests for range adapters --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/iterator_range.h"
#include "llvm/ADT/STLExtras.h"
#include "gtest/gtest.h"
#include <iterator>
#include <list>
#include <vector>
using namespace llvm;
namespace {
// A wrapper around vector which exposes rbegin(), rend().
class ReverseOnlyVector {
std::vector<int> Vec;
public:
ReverseOnlyVector(std::initializer_list<int> list) : Vec(list) {}
typedef std::vector<int>::reverse_iterator reverse_iterator;
reverse_iterator rbegin() { return Vec.rbegin(); }
reverse_iterator rend() { return Vec.rend(); }
};
// A wrapper around vector which exposes begin(), end(), rbegin() and rend().
// begin() and end() don't have implementations as this ensures that we will
// get a linker error if reverse() chooses begin()/end() over rbegin(), rend().
class BidirectionalVector {
std::vector<int> Vec;
public:
BidirectionalVector(std::initializer_list<int> list) : Vec(list) {}
typedef std::vector<int>::iterator iterator;
iterator begin();
iterator end();
typedef std::vector<int>::reverse_iterator reverse_iterator;
reverse_iterator rbegin() { return Vec.rbegin(); }
reverse_iterator rend() { return Vec.rend(); }
};
template <typename R> void TestRev(const R &r) {
int counter = 3;
for (int i : r)
EXPECT_EQ(i, counter--);
}
// Test fixture
template <typename T> class RangeAdapterLValueTest : public ::testing::Test {};
typedef ::testing::Types<std::vector<int>, std::list<int>, int[4]>
RangeAdapterLValueTestTypes;
TYPED_TEST_CASE(RangeAdapterLValueTest, RangeAdapterLValueTestTypes);
TYPED_TEST(RangeAdapterLValueTest, TrivialOperation) {
TypeParam v = {0, 1, 2, 3};
TestRev(reverse(v));
const TypeParam c = {0, 1, 2, 3};
TestRev(reverse(c));
}
template <typename T> struct RangeAdapterRValueTest : testing::Test {};
typedef ::testing::Types<std::vector<int>, std::list<int>, ReverseOnlyVector,
BidirectionalVector> RangeAdapterRValueTestTypes;
TYPED_TEST_CASE(RangeAdapterRValueTest, RangeAdapterRValueTestTypes);
TYPED_TEST(RangeAdapterRValueTest, TrivialOperation) {
TestRev(reverse(TypeParam({0, 1, 2, 3})));
}
} // anonymous namespace