typeindex

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// C++11 <typeindex> -*- C++ -*-
 
// Copyright (C) 2010-2022 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/typeindex
 *  This is a Standard C++ Library header.
 */
 
#ifndef _GLIBCXX_TYPEINDEX
#define _GLIBCXX_TYPEINDEX 1
 
#pragma GCC system_header
 
#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
 
#include <typeinfo>
#if __cplusplus > 201703L
# include <compare>
#endif
 
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
 
  /**
   * @brief Class type_index
   * @ingroup utilities
   *
   *  The class type_index provides a simple wrapper for type_info
   *  which can be used as an index type in associative containers
   *  (23.6) and in unordered associative containers (23.7).
   */
  struct type_index
  {
    type_index(const type_info& __rhs) noexcept
    : _M_target(&__rhs) { }
 
    bool
    operator==(const type_index& __rhs) const noexcept
    { return *_M_target == *__rhs._M_target; }
 
#if ! __cpp_lib_three_way_comparison
    bool
    operator!=(const type_index& __rhs) const noexcept
    { return *_M_target != *__rhs._M_target; }
#endif
 
    bool
    operator<(const type_index& __rhs) const noexcept
    { return _M_target->before(*__rhs._M_target); }
 
    bool
    operator<=(const type_index& __rhs) const noexcept
    { return !__rhs._M_target->before(*_M_target); }
 
    bool
    operator>(const type_index& __rhs) const noexcept
    { return __rhs._M_target->before(*_M_target); }
 
    bool
    operator>=(const type_index& __rhs) const noexcept
    { return !_M_target->before(*__rhs._M_target); }
 
#if __cpp_lib_three_way_comparison
    strong_ordering
    operator<=>(const type_index& __rhs) const noexcept
    {
      if (*_M_target == *__rhs._M_target)
        return strong_ordering::equal;
      if (_M_target->before(*__rhs._M_target))
        return strong_ordering::less;
      return strong_ordering::greater;
    }
#endif
 
    size_t
    hash_code() const noexcept
    { return _M_target->hash_code(); }
 
    const char*
    name() const noexcept
    { return _M_target->name(); }
 
  private:
    const type_info* _M_target;
  };
 
  template<typename _Tp> struct hash;
 
  /// std::hash specialization for type_index.
  template<>
    struct hash<type_index>
    {
      typedef size_t        result_type;
      typedef type_index  argument_type;
 
      size_t
      operator()(const type_index& __ti) const noexcept
      { return __ti.hash_code(); }
    };
 
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
 
#endif  // C++11
 
#endif  // _GLIBCXX_TYPEINDEX