libcxx/include/__charconv/from_chars_floating_point.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___CHARCONV_FROM_CHARS_FLOATING_POINT_H
  11 #define _LIBCPP___CHARCONV_FROM_CHARS_FLOATING_POINT_H
  12
  13 #include <__assert>
  14 #include <__charconv/chars_format.h>
  15 #include <__charconv/from_chars_result.h>
  16 #include <__config>
  17 #include <__cstddef/ptrdiff_t.h>
  18 #include <__system_error/errc.h>
  19
  20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  21 #  pragma GCC system_header
  22 #endif
  23
  24 _LIBCPP_PUSH_MACROS
  25 #include <__undef_macros>
  26
  27 _LIBCPP_BEGIN_NAMESPACE_STD
  28
  29 #if _LIBCPP_STD_VER >= 17
  30
  31 template <class _Fp>
  32 struct __from_chars_result {
  33   _Fp __value;
  34   ptrdiff_t __n;
  35   errc __ec;
  36 };
  37
  38 template <class _Fp>
  39 _LIBCPP_EXPORTED_FROM_ABI __from_chars_result<_Fp> __from_chars_floating_point(
  40     _LIBCPP_NOESCAPE const char* __first, _LIBCPP_NOESCAPE const char* __last, chars_format __fmt);
  41
  42 extern template __from_chars_result<float> __from_chars_floating_point(
  43     _LIBCPP_NOESCAPE const char* __first, _LIBCPP_NOESCAPE const char* __last, chars_format __fmt);
  44
  45 extern template __from_chars_result<double> __from_chars_floating_point(
  46     _LIBCPP_NOESCAPE const char* __first, _LIBCPP_NOESCAPE const char* __last, chars_format __fmt);
  47
  48 template <class _Fp>
  49 _LIBCPP_HIDE_FROM_ABI from_chars_result
  50 __from_chars(const char* __first, const char* __last, _Fp& __value, chars_format __fmt) {
  51   __from_chars_result<_Fp> __r = std::__from_chars_floating_point<_Fp>(__first, __last, __fmt);
  52   if (__r.__ec != errc::invalid_argument)
  53     __value = __r.__value;
  54   return {__first + __r.__n, __r.__ec};
  55 }
  56
  57 _LIBCPP_AVAILABILITY_FROM_CHARS_FLOATING_POINT _LIBCPP_HIDE_FROM_ABI inline from_chars_result
  58 from_chars(const char* __first, const char* __last, float& __value, chars_format __fmt = chars_format::general) {
  59   return std::__from_chars<float>(__first, __last, __value, __fmt);
  60 }
  61
  62 _LIBCPP_AVAILABILITY_FROM_CHARS_FLOATING_POINT _LIBCPP_HIDE_FROM_ABI inline from_chars_result
  63 from_chars(const char* __first, const char* __last, double& __value, chars_format __fmt = chars_format::general) {
  64   return std::__from_chars<double>(__first, __last, __value, __fmt);
  65 }
  66
  67 #endif // _LIBCPP_STD_VER >= 17
  68
  69 _LIBCPP_END_NAMESPACE_STD
  70
  71 _LIBCPP_POP_MACROS
  72
  73 #endif // _LIBCPP___CHARCONV_FROM_CHARS_FLOATING_POINT_H