/* Menes - C++ High-Level Utility Library
 * Copyright (C) 2004-2005  Jay Freeman (saurik)
*/

/*
 *        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.
 * 3. The name of the author may not be used to endorse
 *    or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/

#ifndef MENES_EXT_PREDICATE_HPP
#define MENES_EXT_PREDICATE_HPP

#include "cxx/platform.hpp"
#include "ext/linkage.hpp"

#ifdef MENES_PRAGMA_ONCE
#pragma once
#endif

#include "etl/integral.hpp"
#include "etl/template.hpp"
#include "etl/traits.hpp"

namespace ext {

struct EqualTo {
    template <typename Left_, typename Right_>
    _finline static bool Execute(const Left_ &lhs, const Right_ &rhs) {
        return lhs == rhs;
    }
};

template <typename KeyOf_>
struct KeyEqualTo {
    template <typename Left_, typename Right_>
    _finline static bool Execute(const Left_ &lhs, const Right_ &rhs) {
        return KeyOf_::Execute(lhs) == rhs;
    }
};

struct NotEqualTo {
    template <typename Left_, typename Right_>
    _finline static bool Execute(const Left_ &lhs, const Right_ &rhs) {
        return lhs != rhs;
    }
};

struct LessThan {
    template <typename Left_, typename Right_>
    _finline static bool Execute(const Left_ &lhs, const Right_ &rhs) {
        return lhs < rhs;
    }
};

struct GreaterThan {
    template <typename Left_, typename Right_>
    _finline static bool Execute(const Left_ &lhs, const Right_ &rhs) {
        return lhs > rhs;
    }
};

struct Identity {
    template <typename Arg_>
    _finline static const Arg_ &Execute(const Arg_ &value) {
        return value;
    }
};

struct First {
    template <typename Pair_>
    static const typename Pair_::Head &Execute(const Pair_ &value) {
        return value.First();
    }
};

}

#endif//MENES_EXT_PREDICATE_HPP