libcxx/include/__cxx03/__format/formatter_string.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___CXX03___FORMAT_FORMATTER_STRING_H
  11 #define _LIBCPP___CXX03___FORMAT_FORMATTER_STRING_H
  12
  13 #include <__cxx03/__config>
  14 #include <__cxx03/__format/concepts.h>
  15 #include <__cxx03/__format/format_parse_context.h>
  16 #include <__cxx03/__format/formatter.h>
  17 #include <__cxx03/__format/formatter_output.h>
  18 #include <__cxx03/__format/parser_std_format_spec.h>
  19 #include <__cxx03/__format/write_escaped.h>
  20 #include <__cxx03/string>
  21 #include <__cxx03/string_view>
  22
  23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  24 #  pragma GCC system_header
  25 #endif
  26
  27 _LIBCPP_BEGIN_NAMESPACE_STD
  28
  29 #if _LIBCPP_STD_VER >= 20
  30
  31 template <__fmt_char_type _CharT>
  32 struct _LIBCPP_TEMPLATE_VIS __formatter_string {
  33 public:
  34   template <class _ParseContext>
  35   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
  36     typename _ParseContext::iterator __result = __parser_.__parse(__ctx, __format_spec::__fields_string);
  37     __format_spec::__process_display_type_string(__parser_.__type_);
  38     return __result;
  39   }
  40
  41   template <class _FormatContext>
  42   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
  43   format(basic_string_view<_CharT> __str, _FormatContext& __ctx) const {
  44 #  if _LIBCPP_STD_VER >= 23
  45     if (__parser_.__type_ == __format_spec::__type::__debug)
  46       return __formatter::__format_escaped_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx));
  47 #  endif
  48
  49     return __formatter::__write_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx));
  50   }
  51
  52 #  if _LIBCPP_STD_VER >= 23
  53   _LIBCPP_HIDE_FROM_ABI constexpr void set_debug_format() { __parser_.__type_ = __format_spec::__type::__debug; }
  54 #  endif
  55
  56   __format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left};
  57 };
  58
  59 // Formatter const char*.
  60 template <__fmt_char_type _CharT>
  61 struct _LIBCPP_TEMPLATE_VIS formatter<const _CharT*, _CharT> : public __formatter_string<_CharT> {
  62   using _Base = __formatter_string<_CharT>;
  63
  64   template <class _FormatContext>
  65   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(const _CharT* __str, _FormatContext& __ctx) const {
  66     _LIBCPP_ASSERT_INTERNAL(__str, "The basic_format_arg constructor should have prevented an invalid pointer.");
  67
  68     __format_spec::__parsed_specifications<_CharT> __specs = _Base::__parser_.__get_parsed_std_specifications(__ctx);
  69 #  if _LIBCPP_STD_VER >= 23
  70     if (_Base::__parser_.__type_ == __format_spec::__type::__debug)
  71       return __formatter::__format_escaped_string(basic_string_view<_CharT>{__str}, __ctx.out(), __specs);
  72 #  endif
  73
  74     // When using a center or right alignment and the width option the length
  75     // of __str must be known to add the padding upfront. This case is handled
  76     // by the base class by converting the argument to a basic_string_view.
  77     //
  78     // When using left alignment and the width option the padding is added
  79     // after outputting __str so the length can be determined while outputting
  80     // __str. The same holds true for the precision, during outputting __str it
  81     // can be validated whether the precision threshold has been reached. For
  82     // now these optimizations aren't implemented. Instead the base class
  83     // handles these options.
  84     // TODO FMT Implement these improvements.
  85     if (__specs.__has_width() || __specs.__has_precision())
  86       return __formatter::__write_string(basic_string_view<_CharT>{__str}, __ctx.out(), __specs);
  87
  88     // No formatting required, copy the string to the output.
  89     auto __out_it = __ctx.out();
  90     while (*__str)
  91       *__out_it++ = *__str++;
  92     return __out_it;
  93   }
  94 };
  95
  96 // Formatter char*.
  97 template <__fmt_char_type _CharT>
  98 struct _LIBCPP_TEMPLATE_VIS formatter<_CharT*, _CharT> : public formatter<const _CharT*, _CharT> {
  99   using _Base = formatter<const _CharT*, _CharT>;
 100
 101   template <class _FormatContext>
 102   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(_CharT* __str, _FormatContext& __ctx) const {
 103     return _Base::format(__str, __ctx);
 104   }
 105 };
 106
 107 // Formatter char[].
 108 template <__fmt_char_type _CharT, size_t _Size>
 109 struct _LIBCPP_TEMPLATE_VIS formatter<_CharT[_Size], _CharT> : public __formatter_string<_CharT> {
 110   using _Base = __formatter_string<_CharT>;
 111
 112   template <class _FormatContext>
 113   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
 114   format(const _CharT (&__str)[_Size], _FormatContext& __ctx) const {
 115     return _Base::format(basic_string_view<_CharT>(__str, _Size), __ctx);
 116   }
 117 };
 118
 119 // Formatter std::string.
 120 template <__fmt_char_type _CharT, class _Traits, class _Allocator>
 121 struct _LIBCPP_TEMPLATE_VIS formatter<basic_string<_CharT, _Traits, _Allocator>, _CharT>
 122     : public __formatter_string<_CharT> {
 123   using _Base = __formatter_string<_CharT>;
 124
 125   template <class _FormatContext>
 126   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
 127   format(const basic_string<_CharT, _Traits, _Allocator>& __str, _FormatContext& __ctx) const {
 128     // Drop _Traits and _Allocator to have one std::basic_string formatter.
 129     return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx);
 130   }
 131 };
 132
 133 // Formatter std::string_view.
 134 template <__fmt_char_type _CharT, class _Traits>
 135 struct _LIBCPP_TEMPLATE_VIS formatter<basic_string_view<_CharT, _Traits>, _CharT> : public __formatter_string<_CharT> {
 136   using _Base = __formatter_string<_CharT>;
 137
 138   template <class _FormatContext>
 139   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
 140   format(basic_string_view<_CharT, _Traits> __str, _FormatContext& __ctx) const {
 141     // Drop _Traits to have one std::basic_string_view formatter.
 142     return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx);
 143   }
 144 };
 145
 146 #endif //_LIBCPP_STD_VER >= 20
 147
 148 _LIBCPP_END_NAMESPACE_STD
 149
 150 #endif // _LIBCPP___CXX03___FORMAT_FORMATTER_STRING_H