mirror of
https://github.com/capstone-engine/llvm-capstone.git
synced 2024-11-27 07:31:28 +00:00
2fd4084fca
Finishes implementation of - P2093R14 Formatted output - P2539R4 Should the output of std::print to a terminal be synchronized with the underlying stream? Differential Revision: https://reviews.llvm.org/D156609
59 lines
2.3 KiB
ReStructuredText
59 lines
2.3 KiB
ReStructuredText
.. _implementation-defined-behavior:
|
|
|
|
===============================
|
|
Implementation-defined behavior
|
|
===============================
|
|
|
|
Contains the implementation details of the implementation-defined behavior in
|
|
libc++. Implementation-defined is mandated to be documented by the Standard.
|
|
|
|
.. note:
|
|
This page is far from complete.
|
|
|
|
|
|
Implementation-defined behavior
|
|
===============================
|
|
|
|
Updating the Time Zone Database
|
|
-------------------------------
|
|
|
|
The Standard allows implementations to automatically update the
|
|
*remote time zone database*. Libc++ opts not to do that. Instead calling
|
|
|
|
- ``std::chrono::remote_version()`` will update the version information of the
|
|
*remote time zone database*,
|
|
- ``std::chrono::reload_tzdb()``, if needed, will update the entire
|
|
*remote time zone database*.
|
|
|
|
This offers a way for users to update the *remote time zone database* and
|
|
give them full control over the process.
|
|
|
|
|
|
`[ostream.formatted.print]/3 <http://eel.is/c++draft/ostream.formatted.print#3>`_ A terminal capable of displaying Unicode
|
|
--------------------------------------------------------------------------------------------------------------------------
|
|
|
|
The Standard specifies that the manner in which a stream is determined to refer
|
|
to a terminal capable of displaying Unicode is implementation-defined. This is
|
|
used for ``std::print`` and similar functions taking an ``ostream&`` argument.
|
|
|
|
Libc++ determines that a stream is Unicode-capable terminal by:
|
|
|
|
* First it determines whether the stream's ``rdbuf()`` has an underlying
|
|
``FILE*``. This is ``true`` in the following cases:
|
|
|
|
* The stream is ``std::cout``, ``std::cerr``, or ``std::clog``.
|
|
|
|
* A ``std::basic_filebuf<CharT, Traits>`` derived from ``std::filebuf``.
|
|
|
|
* The way to determine whether this ``FILE*`` refers to a terminal capable of
|
|
displaying Unicode is the same as specified for `void vprint_unicode(FILE*
|
|
stream, string_view fmt, format_args args);
|
|
<http://eel.is/c++draft/print.fun#7>`_. This function is used for other
|
|
``std::print`` overloads that don't take an ``ostream&`` argument.
|
|
|
|
Listed in the index of implementation-defined behavior
|
|
======================================================
|
|
|
|
The order of the entries matches the entries in the
|
|
`draft of the Standard <http://eel.is/c++draft/impldefindex>`_.
|