libstdc++-v3/include/std/forward_list

// <forward_list> -*- C++ -*-

// Copyright (C) 2008-2025 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/>.

/** @file include/forward_list
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_FORWARD_LIST
#define _GLIBCXX_FORWARD_LIST 1

#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif

#include <bits/requires_hosted.h> // containers

#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else

#include <bits/forward_list.h>
#include <bits/range_access.h>
#include <bits/forward_list.tcc>

#ifdef _GLIBCXX_DEBUG
# include <debug/forward_list>
#endif

#define __glibcxx_want_algorithm_default_value_type
#define __glibcxx_want_allocator_traits_is_always_equal
#define __glibcxx_want_containers_ranges
#define __glibcxx_want_erase_if
#define __glibcxx_want_incomplete_container_elements
#define __glibcxx_want_list_remove_return_type
#define __glibcxx_want_nonmember_container_access
#include <bits/version.h>

#if __cplusplus >= 201703L
#include <bits/memory_resource.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
  namespace pmr
  {
    template<typename _Tp>
      using forward_list = std::forward_list<_Tp, polymorphic_allocator<_Tp>>;
  } // namespace pmr
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // C++17

#ifdef __cpp_lib_erase_if // C++ >= 20 && HOSTED
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
  template<typename _Tp, typename _Alloc, typename _Predicate>
    inline typename forward_list<_Tp, _Alloc>::size_type
    erase_if(forward_list<_Tp, _Alloc>& __cont, _Predicate __pred)
    { return __cont.remove_if(__pred); }

  template<typename _Tp, typename _Alloc,
	   typename _Up _GLIBCXX26_DEF_VAL_T(_Tp)>
    inline typename forward_list<_Tp, _Alloc>::size_type
    erase(forward_list<_Tp, _Alloc>& __cont, const _Up& __value)
    {
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 4135. helper lambda of std::erase for list should specify return type
      return std::erase_if(__cont, [&](const auto& __elem) -> bool {
	  return __elem == __value;
      });
    }
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // __cpp_lib_erase_if

#endif // C++11

#endif // _GLIBCXX_FORWARD_LIST