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___FORMAT_FORMATTER_STRING_H 11 #define _LIBCPP___FORMAT_FORMATTER_STRING_H 12 13 #include <__assert> 14 #include <__config> 15 #include <__format/concepts.h> 16 #include <__format/format_parse_context.h> 17 #include <__format/formatter.h> 18 #include <__format/formatter_output.h> 19 #include <__format/parser_std_format_spec.h> 20 #include <__format/write_escaped.h> 21 #include <cstddef> 22 #include <string> 23 #include <string_view> 24 25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 26 # pragma GCC system_header 27 #endif 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 31 #if _LIBCPP_STD_VER >= 20 32 33 template <__fmt_char_type _CharT> 34 struct __formatter_string { 35 public: 36 template <class _ParseContext> parse__formatter_string37 _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) { 38 typename _ParseContext::iterator __result = __parser_.__parse(__ctx, __format_spec::__fields_string); 39 __format_spec::__process_display_type_string(__parser_.__type_); 40 return __result; 41 } 42 43 template <class _FormatContext> 44 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format__formatter_string45 format(basic_string_view<_CharT> __str, _FormatContext& __ctx) const { 46 # if _LIBCPP_STD_VER >= 23 47 if (__parser_.__type_ == __format_spec::__type::__debug) 48 return __formatter::__format_escaped_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx)); 49 # endif 50 51 return __formatter::__write_string(__str, __ctx.out(), __parser_.__get_parsed_std_specifications(__ctx)); 52 } 53 54 # if _LIBCPP_STD_VER >= 23 set_debug_format__formatter_string55 _LIBCPP_HIDE_FROM_ABI constexpr void set_debug_format() { __parser_.__type_ = __format_spec::__type::__debug; } 56 # endif 57 58 __format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left}; 59 }; 60 61 // Formatter const char*. 62 template <__fmt_char_type _CharT> 63 struct formatter<const _CharT*, _CharT> : public __formatter_string<_CharT> { 64 using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>; 65 66 template <class _FormatContext> 67 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(const _CharT* __str, _FormatContext& __ctx) const { 68 _LIBCPP_ASSERT_INTERNAL(__str, "The basic_format_arg constructor should have prevented an invalid pointer."); 69 // Converting the input to a basic_string_view means the data is looped over twice; 70 // - once to determine the length, and 71 // - once to process the data. 72 // 73 // This sounds slower than writing the output directly. However internally 74 // the output algorithms have optimizations for "bulk" operations, which 75 // makes this faster than a single-pass character-by-character output. 76 return _Base::format(basic_string_view<_CharT>(__str), __ctx); 77 } 78 }; 79 80 // Formatter char*. 81 template <__fmt_char_type _CharT> 82 struct formatter<_CharT*, _CharT> : public formatter<const _CharT*, _CharT> { 83 using _Base _LIBCPP_NODEBUG = formatter<const _CharT*, _CharT>; 84 85 template <class _FormatContext> 86 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(_CharT* __str, _FormatContext& __ctx) const { 87 return _Base::format(__str, __ctx); 88 } 89 }; 90 91 // Formatter char[]. 92 template <__fmt_char_type _CharT, size_t _Size> 93 struct formatter<_CharT[_Size], _CharT> : public __formatter_string<_CharT> { 94 using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>; 95 96 template <class _FormatContext> 97 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator 98 format(const _CharT (&__str)[_Size], _FormatContext& __ctx) const { 99 const _CharT* const __pzero = char_traits<_CharT>::find(__str, _Size, _CharT{}); 100 _LIBCPP_ASSERT_VALID_INPUT_RANGE(__pzero != nullptr, "formatting a non-null-terminated array"); 101 return _Base::format(basic_string_view<_CharT>(__str, static_cast<size_t>(__pzero - __str)), __ctx); 102 } 103 }; 104 105 // Formatter std::string. 106 template <__fmt_char_type _CharT, class _Traits, class _Allocator> 107 struct formatter<basic_string<_CharT, _Traits, _Allocator>, _CharT> : public __formatter_string<_CharT> { 108 using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>; 109 110 template <class _FormatContext> 111 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator 112 format(const basic_string<_CharT, _Traits, _Allocator>& __str, _FormatContext& __ctx) const { 113 // Drop _Traits and _Allocator to have one std::basic_string formatter. 114 return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx); 115 } 116 }; 117 118 // Formatter std::string_view. 119 template <__fmt_char_type _CharT, class _Traits> 120 struct formatter<basic_string_view<_CharT, _Traits>, _CharT> : public __formatter_string<_CharT> { 121 using _Base _LIBCPP_NODEBUG = __formatter_string<_CharT>; 122 123 template <class _FormatContext> 124 _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator 125 format(basic_string_view<_CharT, _Traits> __str, _FormatContext& __ctx) const { 126 // Drop _Traits to have one std::basic_string_view formatter. 127 return _Base::format(basic_string_view<_CharT>(__str.data(), __str.size()), __ctx); 128 } 129 }; 130 131 # if _LIBCPP_HAS_WIDE_CHARACTERS 132 template <> 133 struct formatter<char*, wchar_t> : __disabled_formatter {}; 134 template <> 135 struct formatter<const char*, wchar_t> : __disabled_formatter {}; 136 template <size_t _Size> 137 struct formatter<char[_Size], wchar_t> : __disabled_formatter {}; 138 template <class _Traits, class _Allocator> 139 struct formatter<basic_string<char, _Traits, _Allocator>, wchar_t> : __disabled_formatter {}; 140 template <class _Traits> 141 struct formatter<basic_string_view<char, _Traits>, wchar_t> : __disabled_formatter {}; 142 # endif // _LIBCPP_HAS_WIDE_CHARACTERS 143 144 # if _LIBCPP_STD_VER >= 23 145 template <> 146 inline constexpr bool enable_nonlocking_formatter_optimization<char*> = true; 147 template <> 148 inline constexpr bool enable_nonlocking_formatter_optimization<const char*> = true; 149 template <size_t _Size> 150 inline constexpr bool enable_nonlocking_formatter_optimization<char[_Size]> = true; 151 template <class _Traits, class _Allocator> 152 inline constexpr bool enable_nonlocking_formatter_optimization<basic_string<char, _Traits, _Allocator>> = true; 153 template <class _Traits> 154 inline constexpr bool enable_nonlocking_formatter_optimization<basic_string_view<char, _Traits>> = true; 155 156 # if _LIBCPP_HAS_WIDE_CHARACTERS 157 template <> 158 inline constexpr bool enable_nonlocking_formatter_optimization<wchar_t*> = true; 159 template <> 160 inline constexpr bool enable_nonlocking_formatter_optimization<const wchar_t*> = true; 161 template <size_t _Size> 162 inline constexpr bool enable_nonlocking_formatter_optimization<wchar_t[_Size]> = true; 163 template <class _Traits, class _Allocator> 164 inline constexpr bool enable_nonlocking_formatter_optimization<basic_string<wchar_t, _Traits, _Allocator>> = true; 165 template <class _Traits> 166 inline constexpr bool enable_nonlocking_formatter_optimization<basic_string_view<wchar_t, _Traits>> = true; 167 # endif // _LIBCPP_HAS_WIDE_CHARACTERS 168 # endif // _LIBCPP_STD_VER >= 23 169 #endif // _LIBCPP_STD_VER >= 20 170 171 _LIBCPP_END_NAMESPACE_STD 172 173 #endif // _LIBCPP___FORMAT_FORMATTER_STRING_H 174