//

//=======================================================================

// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.

// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek

//

// Distributed under the Boost Software License, Version 1.0. (See

// accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)

//=======================================================================

//

#ifndef BOOST_INDIRECT_CMP_HPP

#define BOOST_INDIRECT_CMP_HPP

#include <functional>

#include <boost/config.hpp>

#include <boost/property_map/property_map.hpp>

namespace boost {

  //: indirect_cmp

  //

  // could also do this with compose_f_gx_hx, and the member binder...

  //

  //!category: functors

  //!component: type

  //!tparam: ReadablePropertyMap - a model of ReadablePropertyMap

  //!definition: functor.h

  template <class ReadablePropertyMap, class Compare>

  class indirect_cmp {

  public:

    typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;

    typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;

    typedef K first_argument_type;

    typedef K second_argument_type;

    typedef bool result_type;

    inline indirect_cmp(const ReadablePropertyMap& df, const Compare& c = Compare())

      : d(df), cmp(c) { }

    template <class A, class B>

    inline bool 

    operator()(const A& u, const B& v) const {

      const T& du = get(d, u);

      const T& dv = get(d, v);

      return cmp(du, dv);

    }

  protected:

    ReadablePropertyMap d;

    Compare cmp;

  };

  template <typename Compare, typename ReadablePropertyMap>

  indirect_cmp<ReadablePropertyMap, Compare>

  make_indirect_cmp(const Compare& cmp, ReadablePropertyMap pmap) {

    indirect_cmp<ReadablePropertyMap, Compare> p(pmap, cmp);

    return p;

  }

  template <class ReadablePropertyMap>

  class indirect_pmap {

  public:

    typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;

    typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;

    typedef K argument_type;

    typedef T result_type;

    inline indirect_pmap(const ReadablePropertyMap& df)

      : d(df) { }

    inline T operator()(const K& u) const {

      return get(d, u);

    }

  protected:

    ReadablePropertyMap d;

  };

  template <typename ReadablePropertyMap>

  indirect_pmap<ReadablePropertyMap>

  make_indirect_pmap(ReadablePropertyMap pmap) {

    indirect_pmap<ReadablePropertyMap> f(pmap);

    return f;

  }

} // namespace boost

#endif // GGCL_INDIRECT_CMP_HPP