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// -*- C++ -*-
// Copyright (C) 2005, 2006, 2009 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) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
// and this permission notice appear in supporting documentation. None
// of the above authors, nor IBM Haifa Research Laboratories, make any
// representation about the suitability of this software for any
// purpose. It is provided "as is" without express or implied
// warranty.
/**
* @file eq_by_less.hpp
* Contains an equivalence function.
*/
#ifndef PB_DS_EQ_BY_LESS_HPP
#define PB_DS_EQ_BY_LESS_HPP
#include <utility>
#include <functional>
#include <vector>
#include <assert.h>
#include <ext/pb_ds/detail/types_traits.hpp>
namespace __gnu_pbds
{
namespace detail
{
template<typename Key, class Cmp_Fn>
struct eq_by_less : private Cmp_Fn
{
bool
operator()(const Key& r_lhs, const Key& r_rhs) const
{
const bool l = Cmp_Fn::operator()(r_lhs, r_rhs);
const bool g = Cmp_Fn::operator()(r_rhs, r_lhs);
return !(l || g);
}
};
} // namespace detail
} // namespace __gnu_pbds
#endif // #ifndef PB_DS_EQ_BY_LESS_HPP