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_CHAR_H
11 #define _LIBCPP___FORMAT_FORMATTER_CHAR_H
12 
13 #include <__availability>
14 #include <__config>
15 #include <__format/format_error.h>
16 #include <__format/format_fwd.h>
17 #include <__format/formatter.h>
18 #include <__format/formatter_integral.h>
19 #include <__format/parser_std_format_spec.h>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #pragma GCC system_header
23 #endif
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 #if _LIBCPP_STD_VER > 17
28 
29 // TODO FMT Remove this once we require compilers with proper C++20 support.
30 // If the compiler has no concepts support, the format header will be disabled.
31 // Without concepts support enable_if needs to be used and that too much effort
32 // to support compilers with partial C++20 support.
33 #if !defined(_LIBCPP_HAS_NO_CONCEPTS)
34 
35 namespace __format_spec {
36 
37 template <class _CharT>
38 class _LIBCPP_TEMPLATE_VIS __parser_char : public __parser_integral<_CharT> {
39 public:
40   _LIBCPP_HIDE_FROM_ABI constexpr auto parse(auto& __parse_ctx)
41       -> decltype(__parse_ctx.begin()) {
42     auto __it = __parser_integral<_CharT>::__parse(__parse_ctx);
43 
44     switch (this->__type) {
45     case _Flags::_Type::__default:
46       this->__type = _Flags::_Type::__char;
47       [[fallthrough]];
48     case _Flags::_Type::__char:
49       this->__handle_char();
50       break;
51 
52     case _Flags::_Type::__binary_lower_case:
53     case _Flags::_Type::__binary_upper_case:
54     case _Flags::_Type::__octal:
55     case _Flags::_Type::__decimal:
56     case _Flags::_Type::__hexadecimal_lower_case:
57     case _Flags::_Type::__hexadecimal_upper_case:
58       this->__handle_integer();
59       break;
60 
61     default:
62       __throw_format_error(
63           "The format-spec type has a type not supported for a char argument");
64     }
65 
66     return __it;
67   }
68 };
69 
70 template <class _CharT>
71 using __formatter_char = __formatter_integral<__parser_char<_CharT>>;
72 
73 } // namespace __format_spec
74 
75 // [format.formatter.spec]/2.1 The specializations
76 
77 template <>
78 struct _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FORMAT formatter<char, char>
79     : public __format_spec::__formatter_char<char> {};
80 
81 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
82 template <>
83 struct _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FORMAT formatter<char, wchar_t>
84     : public __format_spec::__formatter_char<wchar_t> {
85   using _Base = __format_spec::__formatter_char<wchar_t>;
86 
87   _LIBCPP_HIDE_FROM_ABI auto format(char __value, auto& __ctx)
88       -> decltype(__ctx.out()) {
89     return _Base::format(static_cast<wchar_t>(__value), __ctx);
90   }
91 };
92 
93 template <>
94 struct _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FORMAT
95     formatter<wchar_t, wchar_t>
96     : public __format_spec::__formatter_char<wchar_t> {};
97 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
98 #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
99 
100 #endif //_LIBCPP_STD_VER > 17
101 
102 _LIBCPP_END_NAMESPACE_STD
103 
104 #endif // _LIBCPP___FORMAT_FORMATTER_CHAR_H
105