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The C and C++ Include Header Files

/usr/include/c++/11/tr2/type_traits


$ cat -n /usr/include/c++/11/tr2/type_traits

     1	// TR2 <type_traits> -*- C++ -*-
     2	
     3	// Copyright (C) 2011-2021 Free Software Foundation, Inc.
     4	//
     5	// This file is part of the GNU ISO C++ Library.  This library is free
     6	// software; you can redistribute it and/or modify it under the
     7	// terms of the GNU General Public License as published by the
     8	// Free Software Foundation; either version 3, or (at your option)
     9	// any later version.
    10	
    11	// This library is distributed in the hope that it will be useful,
    12	// but WITHOUT ANY WARRANTY; without even the implied warranty of
    13	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    14	// GNU General Public License for more details.
    15	
    16	// Under Section 7 of GPL version 3, you are granted additional
    17	// permissions described in the GCC Runtime Library Exception, version
    18	// 3.1, as published by the Free Software Foundation.
    19	
    20	// You should have received a copy of the GNU General Public License and
    21	// a copy of the GCC Runtime Library Exception along with this program;
    22	// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    23	// <http://www.gnu.org/licenses/>.
    24	
    25	/** @file tr2/type_traits
    26	 *  This is a TR2 C++ Library header.
    27	 */
    28	
    29	#ifndef _GLIBCXX_TR2_TYPE_TRAITS
    30	#define _GLIBCXX_TR2_TYPE_TRAITS 1
    31	
    32	#pragma GCC system_header
    33	#include <type_traits>
    34	#include <bits/c++config.h>
    35	
    36	namespace std _GLIBCXX_VISIBILITY(default)
    37	{
    38	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    39	
    40	namespace tr2
    41	{
    42	  /**
    43	   * @addtogroup metaprogramming
    44	   * @{
    45	   */
    46	
    47	  /**
    48	   *  See N2965: Type traits and base classes
    49	   *  by Michael Spertus
    50	   */
    51	
    52	  /**
    53	   *  Simple typelist. Compile-time list of types.
    54	   */
    55	  template<typename... _Elements>
    56	    struct __reflection_typelist;
    57	
    58	  /// Specialization for an empty typelist.
    59	  template<>
    60	    struct __reflection_typelist<>
    61	    {
    62	      typedef std::true_type					empty;
    63	    };
    64	
    65	  /// Partial specialization.
    66	  template<typename _First, typename... _Rest>
    67	    struct __reflection_typelist<_First, _Rest...>
    68	    {
    69	      typedef std::false_type					empty;
    70	
    71	      struct first
    72	      {
    73		typedef _First						type;
    74	      };
    75	
    76	      struct rest
    77	      {
    78		typedef __reflection_typelist<_Rest...>			type;
    79	      };
    80	    };
    81	
    82	  /// Sequence abstraction metafunctions for manipulating a typelist.
    83	
    84	
    85	
    86	  /// Enumerate all the base classes of a class. Form of a typelist.
    87	  template<typename _Tp>
    88	    struct bases
    89	    {
    90	      typedef __reflection_typelist<__bases(_Tp)...>		type;
    91	    };
    92	
    93	  /// Enumerate all the direct base classes of a class. Form of a typelist.
    94	  template<typename _Tp>
    95	    struct direct_bases
    96	    {
    97	      typedef __reflection_typelist<__direct_bases(_Tp)...>	type;
    98	    };
    99	
   100	  /// @} group metaprogramming
   101	}
   102	
   103	_GLIBCXX_END_NAMESPACE_VERSION
   104	}
   105	
   106	#endif // _GLIBCXX_TR2_TYPE_TRAITS