source: source/ariba/overlay/modules/chord/detail/comparators.hpp@ 4703

// [License]
// The Ariba-Underlay Copyright
//
// Copyright (c) 2008-2009, Institute of Telematics, UniversitÀt Karlsruhe (TH)
//
// Institute of Telematics
// UniversitÀt Karlsruhe (TH)
// Zirkel 2, 76128 Karlsruhe
// Germany
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE INSTITUTE OF TELEMATICS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OF TELEMATICS OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// The views and conclusions contained in the software and documentation
// are those of the authors and should not be interpreted as representing
// official policies, either expressed or implied, of the Institute of
// Telematics.
// [License]
#ifndef COMPARATORS_HPP_
#define COMPARATORS_HPP_

/**
 * TODO: Doc
 *
 * @author Sebastian Mies <mies@tm.uka.de>
 */
#include "distances.hpp"

namespace comparators {

using namespace distances;

/// default compare operation
struct default_compare {
        template<typename T>
        int operator ()(const T& x, const T& y) {
                return x == y ? 0 : (x < y ? -1 : 1);
        }
};

/// compares distances to a given center point
template<class CenterType, class T, class Distance = default_distance,
                class Compare = default_compare>
class distance_compare {
private:
        CenterType center;
        Distance distance;
        Compare compare;

public:
        explicit distance_compare(CenterType center,
                        Distance distance = Distance(), Compare compare = Compare()) :
                center(center), distance(distance), compare(compare) {
        }

        const CenterType get_center() const {
                return center;
        }

        int operator ()(const T& x, const T& y) {
                return compare(distance(center, x), distance(center, y));
        }
};

}

#endif /* COMPARATORS_HPP_ */