libcxx/include/__format/container_adaptor.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___FORMAT_CONTAINER_ADAPTOR_H
  11 #define _LIBCPP___FORMAT_CONTAINER_ADAPTOR_H
  12
  13 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  14 #  pragma GCC system_header
  15 #endif
  16
  17 #include <__config>
  18 #include <__format/concepts.h>
  19 #include <__format/formatter.h>
  20 #include <__format/range_default_formatter.h>
  21 #include <__ranges/ref_view.h>
  22 #include <__type_traits/is_const.h>
  23 #include <__type_traits/maybe_const.h>
  24 #include <queue>
  25 #include <stack>
  26
  27 _LIBCPP_BEGIN_NAMESPACE_STD
  28
  29 #if _LIBCPP_STD_VER >= 23
  30
  31 // [container.adaptors.format] only specifies the library should provide the
  32 // formatter specializations, not which header should provide them.
  33 // Since <format> includes a lot of headers, add these headers here instead of
  34 // adding more dependencies like, locale, optinal, string, tuple, etc. to the
  35 // adaptor headers. To use the format functions users already include <format>.
  36
  37 template <class _Adaptor, class _CharT>
  38 struct _LIBCPP_TEMPLATE_VIS __formatter_container_adaptor {
  39 private:
  40   using __maybe_const_container = __fmt_maybe_const<typename _Adaptor::container_type, _CharT>;
  41   using __maybe_const_adaptor   = __maybe_const<is_const_v<__maybe_const_container>, _Adaptor>;
  42   formatter<ranges::ref_view<__maybe_const_container>, _CharT> __underlying_;
  43
  44 public:
  45   template <class _ParseContext>
  46   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
  47     return __underlying_.parse(__ctx);
  48   }
  49
  50   template <class _FormatContext>
  51   _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
  52   format(__maybe_const_adaptor& __adaptor, _FormatContext& __ctx) const {
  53     return __underlying_.format(__adaptor.__get_container(), __ctx);
  54   }
  55 };
  56
  57 template <class _CharT, class _Tp, formattable<_CharT> _Container>
  58 struct _LIBCPP_TEMPLATE_VIS formatter<queue<_Tp, _Container>, _CharT>
  59     : public __formatter_container_adaptor<queue<_Tp, _Container>, _CharT> {};
  60
  61 template <class _CharT, class _Tp, class _Container, class _Compare>
  62 struct _LIBCPP_TEMPLATE_VIS formatter<priority_queue<_Tp, _Container, _Compare>, _CharT>
  63     : public __formatter_container_adaptor<priority_queue<_Tp, _Container, _Compare>, _CharT> {};
  64
  65 template <class _CharT, class _Tp, formattable<_CharT> _Container>
  66 struct _LIBCPP_TEMPLATE_VIS formatter<stack<_Tp, _Container>, _CharT>
  67     : public __formatter_container_adaptor<stack<_Tp, _Container>, _CharT> {};
  68
  69 #endif //_LIBCPP_STD_VER >= 23
  70
  71 _LIBCPP_END_NAMESPACE_STD
  72
  73 #endif // _LIBCPP___FORMAT_CONTAINER_ADAPTOR_H