llvm-project/libcxx/include/uchar.h
Tom Honermann 7e7013c5d4 [libc++][cuchar] Declare std::c8rtomb and std::mbrtoc8 in <cuchar> if available.
This change implements the C library dependent portions of P0482R6
(char8_t: A type for UTF-8 characters and strings (Revision 6)) by
declaring std::c8rtomb() and std::mbrtoc8() in the <cuchar> header
when implementations are provided by the C library as specified by
WG14 N2653 (char8_t: A type for UTF-8 characters and strings
(Revision 1)) as adopted for C23.

A _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8 macro is defined by the libc++ __config
header unless it is known that the C library provides these functions
in the current compilation mode. This macro is used for testing purposes
and may be of use to libc++ users. At present, the only C library known
to implement these functions is GNU libc as of its 2.36 release.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D130946
2022-09-10 21:10:33 -04:00

55 lines
1.5 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_UCHAR_H
#define _LIBCPP_UCHAR_H
/*
uchar.h synopsis // since C++11
Macros:
__STDC_UTF_16__
__STDC_UTF_32__
Types:
mbstate_t
size_t
size_t mbrtoc8(char8_t* pc8, const char* s, size_t n, mbstate_t* ps); // since C++20
size_t c8rtomb(char* s, char8_t c8, mbstate_t* ps); // since C++20
size_t mbrtoc16(char16_t* pc16, const char* s, size_t n, mbstate_t* ps);
size_t c16rtomb(char* s, char16_t c16, mbstate_t* ps);
size_t mbrtoc32(char32_t* pc32, const char* s, size_t n, mbstate_t* ps);
size_t c32rtomb(char* s, char32_t c32, mbstate_t* ps);
*/
#include <__config>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if !defined(_LIBCPP_CXX03_LANG)
// Some platforms don't implement <uchar.h> and we don't want to give a hard
// error on those platforms. When the platform doesn't provide <uchar.h>, at
// least include <stddef.h> so we get the declaration for size_t.
#if __has_include_next(<uchar.h>)
# include_next <uchar.h>
#else
# include <stddef.h>
#endif
#endif // _LIBCPP_CXX03_LANG
#endif // _LIBCPP_UCHAR_H