Files
gcc/libstdc++-v3/include/std/queue
Tomasz Kamiński bacf741a92 libstdc++: Implement formatters for queue, priority_queue and stack [PR109162]
This patch implements formatter specializations for standard container adaptors
(queue, priority_queue and stack) from P2286R8.

To be able to access the protected `c` member, the adaptors befriend
corresponding formatter specializations. Note that such specialization
may be disable if the container is formattable, in such case
specializations are unharmful.

As in the case of previous commits, the signatures of the user-facing parse
and format methods of the provided formatters deviate from the standard by
constraining types of parameters:
 * _CharT is constrained __formatter::__char
 * basic_format_parse_context<_CharT> for parse argument
 * basic_format_context<_Out, _CharT> for format second argument
The standard specifies all above as unconstrained types. In particular
_CharT constrain, allow us to befriend all allowed specializations.

Furthermore the standard specifies these formatters as delegating to
formatter<ranges::ref_view<const? _Container>, charT>, which in turn
delegates to range_formatter. This patch avoids one level of indirection,
and dependency of ranges::ref_view.  This is technically observable if
user specializes formatter<std::ref_view<PD>> where PD is program defined
container, but I do not think this is the case worth extra indirection.

This patch also moves the formattable and it's dependencies to the formatfwd.h,
so it can be used in adapters formatters, without including format header.
The definition of _Iter_for is changed from alias to denoting
back_insert_iterator<basic_string<_CharT>>, to struct with type nested typedef
that points to same type, that is forward declared.

	PR libstdc++/109162

libstdc++-v3/ChangeLog:

	* include/bits/formatfwd.h (__format::__parsable_with)
	(__format::__formattable_with, __format::__formattable_impl)
	(__format::__has_debug_format, __format::__const_formattable_range)
	(__format::__maybe_const_range, __format::__maybe_const)
	(std::formattable): Moved from std/format.
	(__format::Iter_for, std::range_formatter): Forward declare.
	* include/bits/stl_queue.h (std::formatter): Forward declare.
	(std::queue, std::priority_queue): Befriend formatter specializations.
	* include/bits/stl_stack.h (std::formatter): Forward declare.
	(std::stack): Befriend formatter specializations.
	* include/std/format (__format::_Iter_for): Define as struct with
	(__format::__parsable_with, __format::__formattable_with)
	(__format::__formattable_impl, __format::__has_debug_format)
	(_format::__const_formattable_range, __format::__maybe_const_range)
	(__format::__maybe_const, std::formattable): Moved to bits/formatfwd.h.
	(std::range_formatter): Remove default argument specified in declaration
	in bits/formatfwd.h.
	* include/std/queue: Include bits/version.h before bits/stl_queue.h.
	(formatter<queue<_Tp, _Container, _Compare>, _CharT>)
	(formatter<priority_queue<_Tp, _Container, _Compare>, _CharT>): Define.
	* include/std/stack: Include bits/version.h before bits/stl_stack.h
	(formatter<stack<_Tp, _Container, _Compare>, _CharT>): Define.
	* testsuite/std/format/ranges/adaptors.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
2025-04-25 13:02:04 +02:00

149 lines
5.1 KiB
C++

// <queue> -*- C++ -*-
// Copyright (C) 2001-2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file include/queue
* This is a Standard C++ Library header.
*/
#ifndef _GLIBCXX_QUEUE
#define _GLIBCXX_QUEUE 1
#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif
#include <bits/requires_hosted.h> // containers
#define __glibcxx_want_adaptor_iterator_pair_constructor
#define __glibcxx_want_containers_ranges
#include <bits/version.h>
#include <deque>
#include <vector>
#include <bits/stl_heap.h>
#include <bits/stl_function.h>
#include <bits/stl_queue.h>
#ifdef __glibcxx_format_ranges // C++ >= 23 && HOSTED
#include <bits/formatfwd.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// Standard does not constrain accepted _CharT, we do so we can
// befriend specializations.
template<__format::__char _CharT, typename _Tp,
formattable<_CharT> _Container>
struct formatter<queue<_Tp, _Container>, _CharT>
{
private:
using __maybe_const_adaptor
= __conditional_t<
__format::__const_formattable_range<_Container, _CharT>,
const queue<_Tp, _Container>, queue<_Tp, _Container>>;
public:
// Standard declares this as template accepting unconstrained
// ParseContext type.
constexpr typename basic_format_parse_context<_CharT>::iterator
parse(basic_format_parse_context<_CharT>& __pc)
{ return _M_f.parse(__pc); }
// Standard declares this as template accepting unconstrained
// FormatContext type.
template<typename _Out>
typename basic_format_context<_Out, _CharT>::iterator
format(__maybe_const_adaptor& __a,
basic_format_context<_Out, _CharT>& __fc) const
{ return _M_f.format(__a.c, __fc); }
private:
// Standard uses formatter<ref_view<_Container>, _CharT>.
range_formatter<_Tp, _CharT> _M_f;
};
template<__format::__char _CharT, typename _Tp,
formattable<_CharT> _Container, typename _Compare>
struct formatter<priority_queue<_Tp, _Container, _Compare>, _CharT>
{
private:
using __maybe_const_adaptor
= __conditional_t<
__format::__const_formattable_range<_Container, _CharT>,
const priority_queue<_Tp, _Container, _Compare>,
priority_queue<_Tp, _Container, _Compare>>;
public:
// Standard declares this as template accepting unconstrained
// ParseContext type.
constexpr typename basic_format_parse_context<_CharT>::iterator
parse(basic_format_parse_context<_CharT>& __pc)
{ return _M_f.parse(__pc); }
// Standard declares this as template accepting unconstrained
// FormatContext type.
template<typename _Out>
typename basic_format_context<_Out, _CharT>::iterator
format(__maybe_const_adaptor& __a,
basic_format_context<_Out, _CharT>& __fc) const
{ return _M_f.format(__a.c, __fc); }
private:
// Standard uses formatter<ref_view<_Container>, _CharT>.
range_formatter<_Tp, _CharT> _M_f;
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // __glibcxx_format_ranges
#endif /* _GLIBCXX_QUEUE */