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  1//===---------------------------------------------------------------------===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===---------------------------------------------------------------------===//
  8
  9#ifndef _LIBCPP___OSTREAM_PRINT_H
 10#define _LIBCPP___OSTREAM_PRINT_H
 11
 12#include <__config>
 13
 14#if _LIBCPP_HAS_LOCALIZATION
 15
 16#  include <__fwd/ostream.h>
 17#  include <__iterator/ostreambuf_iterator.h>
 18#  include <__ostream/basic_ostream.h>
 19#  include <format>
 20#  include <ios>
 21#  include <print>
 22#  include <streambuf>
 23
 24#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 25#    pragma GCC system_header
 26#  endif
 27
 28_LIBCPP_BEGIN_NAMESPACE_STD
 29
 30#  if _LIBCPP_STD_VER >= 23
 31
 32template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
 33_LIBCPP_HIDE_FROM_ABI inline void
 34__vprint_nonunicode(ostream& __os, string_view __fmt, format_args __args, bool __write_nl) {
 35  // [ostream.formatted.print]/3
 36  // Effects: Behaves as a formatted output function
 37  // ([ostream.formatted.reqmts]) of os, except that:
 38  // - failure to generate output is reported as specified below, and
 39  // - any exception thrown by the call to vformat is propagated without regard
 40  //   to the value of os.exceptions() and without turning on ios_base::badbit
 41  //   in the error state of os.
 42  // After constructing a sentry object, the function initializes an automatic
 43  // variable via
 44  //   string out = vformat(os.getloc(), fmt, args);
 45
 46  ostream::sentry __s(__os);
 47  if (__s) {
 48    string __o = std::vformat(__os.getloc(), __fmt, __args);
 49    if (__write_nl)
 50      __o += '\n';
 51
 52#    if _LIBCPP_HAS_EXCEPTIONS
 53    try {
 54#    endif // _LIBCPP_HAS_EXCEPTIONS
 55      if (auto __rdbuf = __os.rdbuf();
 56          !__rdbuf || __rdbuf->sputn(__o.data(), __o.size()) != static_cast<streamsize>(__o.size()))
 57        __os.setstate(ios_base::badbit | ios_base::failbit);
 58
 59#    if _LIBCPP_HAS_EXCEPTIONS
 60    } catch (...) {
 61      __os.__set_badbit_and_consider_rethrow();
 62    }
 63#    endif // _LIBCPP_HAS_EXCEPTIONS
 64  }
 65}
 66
 67template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
 68_LIBCPP_HIDE_FROM_ABI inline void vprint_nonunicode(ostream& __os, string_view __fmt, format_args __args) {
 69  std::__vprint_nonunicode(__os, __fmt, __args, false);
 70}
 71
 72// Returns the FILE* associated with the __os.
 73// Returns a nullptr when no FILE* is associated with __os.
 74// This function is in the dylib since the type of the buffer associated
 75// with std::cout, std::cerr, and std::clog is only known in the dylib.
 76//
 77// This function implements part of the implementation-defined behavior
 78// of [ostream.formatted.print]/3
 79//   If the function is vprint_unicode and os is a stream that refers to
 80//   a terminal capable of displaying Unicode which is determined in an
 81//   implementation-defined manner, writes out to the terminal using the
 82//   native Unicode API;
 83// Whether the returned FILE* is "a terminal capable of displaying Unicode"
 84// is determined in the same way as the print(FILE*, ...) overloads.
 85_LIBCPP_EXPORTED_FROM_ABI FILE* __get_ostream_file(ostream& __os);
 86
 87#    if _LIBCPP_HAS_UNICODE
 88template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
 89_LIBCPP_HIDE_FROM_ABI void __vprint_unicode(ostream& __os, string_view __fmt, format_args __args, bool __write_nl) {
 90#      if _LIBCPP_AVAILABILITY_HAS_PRINT == 0
 91  return std::__vprint_nonunicode(__os, __fmt, __args, __write_nl);
 92#      else
 93  FILE* __file = std::__get_ostream_file(__os);
 94  if (!__file || !__print::__is_terminal(__file))
 95    return std::__vprint_nonunicode(__os, __fmt, __args, __write_nl);
 96
 97  // [ostream.formatted.print]/3
 98  //    If the function is vprint_unicode and os is a stream that refers to a
 99  //    terminal capable of displaying Unicode which is determined in an
100  //    implementation-defined manner, writes out to the terminal using the
101  //    native Unicode API; if out contains invalid code units, the behavior is
102  //    undefined and implementations are encouraged to diagnose it. If the
103  //    native Unicode API is used, the function flushes os before writing out.
104  //
105  // This is the path for the native API, start with flushing.
106  __os.flush();
107
108#        if _LIBCPP_HAS_EXCEPTIONS
109  try {
110#        endif // _LIBCPP_HAS_EXCEPTIONS
111    ostream::sentry __s(__os);
112    if (__s) {
113#        ifndef _LIBCPP_WIN32API
114      __print::__vprint_unicode_posix(__file, __fmt, __args, __write_nl, true);
115#        elif _LIBCPP_HAS_WIDE_CHARACTERS
116    __print::__vprint_unicode_windows(__file, __fmt, __args, __write_nl, true);
117#        else
118#          error "Windows builds with wchar_t disabled are not supported."
119#        endif
120    }
121
122#        if _LIBCPP_HAS_EXCEPTIONS
123  } catch (...) {
124    __os.__set_badbit_and_consider_rethrow();
125  }
126#        endif // _LIBCPP_HAS_EXCEPTIONS
127#      endif   // _LIBCPP_AVAILABILITY_HAS_PRINT
128}
129
130template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
131_LIBCPP_HIDE_FROM_ABI inline void vprint_unicode(ostream& __os, string_view __fmt, format_args __args) {
132  std::__vprint_unicode(__os, __fmt, __args, false);
133}
134#    endif // _LIBCPP_HAS_UNICODE
135
136template <class... _Args>
137_LIBCPP_HIDE_FROM_ABI void print(ostream& __os, format_string<_Args...> __fmt, _Args&&... __args) {
138#    if _LIBCPP_HAS_UNICODE
139  if constexpr (__print::__use_unicode_execution_charset)
140    std::__vprint_unicode(__os, __fmt.get(), std::make_format_args(__args...), false);
141  else
142    std::__vprint_nonunicode(__os, __fmt.get(), std::make_format_args(__args...), false);
143#    else  // _LIBCPP_HAS_UNICODE
144  std::__vprint_nonunicode(__os, __fmt.get(), std::make_format_args(__args...), false);
145#    endif // _LIBCPP_HAS_UNICODE
146}
147
148template <class... _Args>
149_LIBCPP_HIDE_FROM_ABI void println(ostream& __os, format_string<_Args...> __fmt, _Args&&... __args) {
150#    if _LIBCPP_HAS_UNICODE
151  // Note the wording in the Standard is inefficient. The output of
152  // std::format is a std::string which is then copied. This solution
153  // just appends a newline at the end of the output.
154  if constexpr (__print::__use_unicode_execution_charset)
155    std::__vprint_unicode(__os, __fmt.get(), std::make_format_args(__args...), true);
156  else
157    std::__vprint_nonunicode(__os, __fmt.get(), std::make_format_args(__args...), true);
158#    else  // _LIBCPP_HAS_UNICODE
159  std::__vprint_nonunicode(__os, __fmt.get(), std::make_format_args(__args...), true);
160#    endif // _LIBCPP_HAS_UNICODE
161}
162
163template <class = void> // TODO PRINT template or availability markup fires too eagerly (http://llvm.org/PR61563).
164_LIBCPP_HIDE_FROM_ABI inline void println(ostream& __os) {
165  std::print(__os, "\n");
166}
167
168#  endif // _LIBCPP_STD_VER >= 23
169
170_LIBCPP_END_NAMESPACE_STD
171
172#endif // _LIBCPP_HAS_LOCALIZATION
173
174#endif // _LIBCPP___OSTREAM_PRINT_H