comparator.h

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// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; c-file-style: "stroustrup"; -*-
// vi:set ts=4 sts=4 sw=4 noet :
// Copyright 2008, 2012, The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE is free software: you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
// 
// TPIE 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 Lesser General Public
// License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with TPIE.  If not, see <http://www.gnu.org/licenses/>

#ifndef _COMPARATOR_H
#define _COMPARATOR_H


// Get definitions for working with Unix and Windows
#include <tpie/config.h>
#include <tpie/portability.h>

namespace tpie {

// In is unlikely that users will need to directly need these classes
// except to maybe upgrade old code with minimal changes. In the future it
// may be better to make TPIE's compare() method match the syntax of the
// STL operator ()

template<class T, class STLCMP>
class STL2TPIE_cmp{
public:
    STL2TPIE_cmp(STLCMP* cmp) : m_isLess(cmp) {
        // Does nothing.
    }

    inline int compare(const T& left, const T& right){
        if( (*m_isLess)(left, right) ){ return -1; }
        else { return 0; }
    }

private:
    STLCMP *m_isLess;
};

template<class T, class TPCMP>
class TPIE2STL_cmp{
public:
    TPIE2STL_cmp(TPCMP* cmp) : m_cmpobj(cmp) {
        // Does nothing.
    }

    inline bool operator()(const T& left, const T& right) const{
        return (m_cmpobj->compare(left, right) < 0);
    }

private:
    TPCMP* m_cmpobj;
};

template<class T>
class op2TPIE_cmp{
public:
    op2TPIE_cmp() {
        // Does nothing.
    }

    inline int compare(const T& left, const T& right){
        if( left < right ){ return -1; }
        else { return 0; }
    }
};

}  //  tpie namespace

#endif // _COMPARATOR_H