1 //
2 //=======================================================================
3 // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
4 // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
5 //
6 // Distributed under the Boost Software License, Version 1.0. (See
7 // accompanying file LICENSE_1_0.txt or copy at
8 // http://www.boost.org/LICENSE_1_0.txt)
9 //=======================================================================
10 //
11 
12 #ifndef BOOST_INDIRECT_CMP_HPP
13 #define BOOST_INDIRECT_CMP_HPP
14 
15 #include <functional>
16 #include <boost/config.hpp>
17 #include <boost/property_map/property_map.hpp>
18 
19 namespace boost {
20 
21   //: indirect_cmp
22   //
23   // could also do this with compose_f_gx_hx, and the member binder...
24   //
25   //!category: functors
26   //!component: type
27   //!tparam: ReadablePropertyMap - a model of ReadablePropertyMap
28   //!definition: functor.h
29   template <class ReadablePropertyMap, class Compare>
30   class indirect_cmp {
31   public:
32     typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;
33     typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;
34     typedef K first_argument_type;
35     typedef K second_argument_type;
36     typedef bool result_type;
indirect_cmp(const ReadablePropertyMap & df,const Compare & c=Compare ())37     inline indirect_cmp(const ReadablePropertyMap& df, const Compare& c = Compare())
38       : d(df), cmp(c) { }
39 
40     template <class A, class B>
41     inline bool
operator ()(const A & u,const B & v) const42     operator()(const A& u, const B& v) const {
43       const T& du = get(d, u);
44       const T& dv = get(d, v);
45       return cmp(du, dv);
46     }
47   protected:
48     ReadablePropertyMap d;
49     Compare cmp;
50   };
51 
52   template <typename Compare, typename ReadablePropertyMap>
53   indirect_cmp<ReadablePropertyMap, Compare>
make_indirect_cmp(const Compare & cmp,ReadablePropertyMap pmap)54   make_indirect_cmp(const Compare& cmp, ReadablePropertyMap pmap) {
55     indirect_cmp<ReadablePropertyMap, Compare> p(pmap, cmp);
56     return p;
57   }
58 
59   template <class ReadablePropertyMap>
60   class indirect_pmap {
61   public:
62     typedef typename boost::property_traits<ReadablePropertyMap>::value_type T;
63     typedef typename boost::property_traits<ReadablePropertyMap>::key_type K;
64     typedef K argument_type;
65     typedef T result_type;
indirect_pmap(const ReadablePropertyMap & df)66     inline indirect_pmap(const ReadablePropertyMap& df)
67       : d(df) { }
68 
operator ()(const K & u) const69     inline T operator()(const K& u) const {
70       return get(d, u);
71     }
72   protected:
73     ReadablePropertyMap d;
74   };
75 
76   template <typename ReadablePropertyMap>
77   indirect_pmap<ReadablePropertyMap>
make_indirect_pmap(ReadablePropertyMap pmap)78   make_indirect_pmap(ReadablePropertyMap pmap) {
79     indirect_pmap<ReadablePropertyMap> f(pmap);
80     return f;
81   }
82 
83 
84 } // namespace boost
85 
86 
87 #endif // GGCL_INDIRECT_CMP_HPP
88