williamr@2: //
williamr@2: //=======================================================================
williamr@2: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
williamr@2: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0. (See
williamr@2: // accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: //=======================================================================
williamr@2: //
williamr@2: 
williamr@2: #ifndef BOOST_INDIRECT_CMP_HPP
williamr@2: #define BOOST_INDIRECT_CMP_HPP
williamr@2: 
williamr@2: #include <functional>
williamr@2: #include <boost/config.hpp>
williamr@2: #include <boost/property_map.hpp>
williamr@2: 
williamr@2: namespace boost {
williamr@2: 
williamr@2:   //: indirect_cmp
williamr@2:   //
williamr@2:   // could also do this with compose_f_gx_hx, and the member binder...
williamr@2:   //
williamr@2:   //!category: functors
williamr@2:   //!component: type
williamr@2:   //!tparam: ReadablePropertyMap - a model of ReadablePropertyMap
williamr@2:   //!definition: functor.h
williamr@2:   template <class ReadablePropertyMap, class Compare>
williamr@2:   class indirect_cmp {
williamr@2:   public:
williamr@2:     typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;
williamr@2:     typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;
williamr@2:     typedef K first_argument_type;
williamr@2:     typedef K second_argument_type;
williamr@2:     typedef T result_type;
williamr@2:     inline indirect_cmp(const ReadablePropertyMap& df, const Compare& c = Compare())
williamr@2:       : d(df), cmp(c) { }
williamr@2: 
williamr@2:     template <class A, class B>
williamr@2:     inline bool 
williamr@2:     operator()(const A& u, const B& v) const {
williamr@2:       T du = get(d, u), dv = get(d, v);
williamr@2:       return cmp(du, dv);
williamr@2:     }
williamr@2:   protected:
williamr@2:     ReadablePropertyMap d;
williamr@2:     Compare cmp;
williamr@2:   };
williamr@2: 
williamr@2:   template <typename Compare, typename ReadablePropertyMap>
williamr@2:   indirect_cmp<ReadablePropertyMap, Compare>
williamr@2:   make_indirect_cmp(const Compare& cmp, ReadablePropertyMap pmap) {
williamr@2:     indirect_cmp<ReadablePropertyMap, Compare> p(pmap, cmp);
williamr@2:     return p;
williamr@2:   }
williamr@2: 
williamr@2:   template <class ReadablePropertyMap>
williamr@2:   class indirect_pmap {
williamr@2:   public:
williamr@2:     typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;
williamr@2:     typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;
williamr@2:     typedef K argument_type;
williamr@2:     typedef T result_type;
williamr@2:     inline indirect_pmap(const ReadablePropertyMap& df)
williamr@2:       : d(df) { }
williamr@2: 
williamr@2:     inline bool operator()(const K& u) const {
williamr@2:       return get(d, u);
williamr@2:     }
williamr@2:   protected:
williamr@2:     ReadablePropertyMap d;
williamr@2:   };
williamr@2: 
williamr@2:   template <typename ReadablePropertyMap>
williamr@2:   indirect_pmap<ReadablePropertyMap>
williamr@2:   make_indirect_pmap(ReadablePropertyMap pmap) {
williamr@2:     indirect_pmap<ReadablePropertyMap> f(pmap);
williamr@2:     return f;
williamr@2:   }
williamr@2: 
williamr@2: 
williamr@2: } // namespace boost
williamr@2: 
williamr@2: 
williamr@2: #endif // GGCL_INDIRECT_CMP_HPP