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  #   €l–дY>”ЉC]Љm@‚аEq·”ЕЈБ„B|_Аї 7Ф    // Functional extensions -*- C++ -*-

// Copyright (C) 2002-2013 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
 * 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 ext/functional
 *  This file is a GNU extension to the Standard C++ Library (possibly
 *  containing extensions from the HP/SGI STL subset).
 */

#ifndef _EXT_FUNCTIONAL
#define _EXT_FUNCTIONAL 1

#pragma GCC system_header

#include <functional>

namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  using std::size_t;
  using std::unary_function;
  using std::binary_function;
  using std::mem_fun1_t;
  using std::const_mem_fun1_t;
  using std::mem_fun1_ref_t;
  using std::const_mem_fun1_ref_t;

  /** The @c identity_element functions are not part of the C++
   *  standard; SGI provided them as an extension.  Its argument is an
   *  operation, and its return value is the identity element for that
   *  operation.  It is overloaded for addition and multiplication,
   *  and you can overload it for your own nefarious operations.
   *
   *  @addtogroup SGIextensions
   *  @{
   */
  /// An \link SGIextensions SGI extension \endlink.
  template <class _Tp>
    inline _Tp
    identity_element(std::plus<_Tp>)
    { return _Tp(0); }

  /// An \link SGIextensions SGI extension \endlink.
  template <class _Tp>
    inline _Tp
    identity_element(std::multiplies<_Tp>)
    { return _Tp(1); }
  /** @}  */
  
  /** As an extension to the binders, SGI provided composition functors and
   *  wrapper functions to aid in their creation.  The @c unary_compose
   *  functor is constructed from two functions/functors, @c f and @c g.
   *  Calling @c operator() with a single argument @c x returns @c f(g(x)).
   *  The function @c compose1 takes the two functions and constructs a
   *  @c unary_compose variable for you.
   *
   *  @c binary_compose is constructed from three functors, @c f, @c g1,
   *  and @c g2.  Its @c operator() returns @c f(g1(x),g2(x)).  The function
   *  compose2 takes f, g1, and g2,