projects / ceph.git / blame
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| 7c673cae FG |
1 | // Copyright (C) 2013 Eurodecision |
| 2 | // Authors: Guillaume Pinot | |
| 3 | // | |
| 4 | // Distributed under the Boost Software License, Version 1.0. (See | |
| 5 | // accompanying file LICENSE_1_0.txt or copy at | |
| 6 | // http://www.boost.org/LICENSE_1_0.txt) | |
| 7 | // | |
| 8 | // See http://www.boost.org/libs/property_map for documentation. | |
| 9 | ||
| 10 | #ifndef BOOST_PROPERTY_MAP_COMPOSE_PROPERTY_MAP_HPP | |
| 11 | #define BOOST_PROPERTY_MAP_COMPOSE_PROPERTY_MAP_HPP | |
| 12 | ||
| 13 | #include <boost/property_map/property_map.hpp> | |
| 14 | #include <boost/type_traits.hpp> | |
| 15 | ||
| 16 | namespace boost { | |
| 17 | ||
| 18 | // A compose property map: make_compose_property_map(f, g)[x] == f[g[x]] | |
| 19 | // | |
| 20 | // g must be a readable property map. | |
| 21 | // The category of compose_property_map(f, g) is the category of f. | |
| 22 | ||
| 23 | template <typename FPMap, typename GPMap> | |
| 24 | class compose_property_map | |
| 25 | { | |
| 26 | public: | |
| 27 | typedef typename boost::property_traits<FPMap>::category category; | |
| 28 | typedef typename boost::property_traits<GPMap>::key_type key_type; | |
| 29 | typedef typename boost::property_traits<FPMap>::value_type value_type; | |
| 30 | typedef typename boost::property_traits<FPMap>::reference reference; | |
| 31 | ||
| 32 | inline compose_property_map(const FPMap &f_p, const GPMap &g_p): | |
| 33 | f(f_p), g(g_p) | |
| 34 | {} | |
| 35 | ||
| 36 | inline compose_property_map() {} | |
| 37 | ||
| 38 | inline reference | |
| 39 | operator[](const key_type &v) const { | |
| 40 | return f[get(g, v)]; | |
| 41 | } | |
| 42 | ||
| 43 | // return type of get(): | |
| 44 | // if (reference is not a ref) | |
| 45 | // value_type | |
| 46 | // else if (reference is const) | |
| 47 | // reference | |
| 48 | // else | |
| 49 | // const value_type& | |
| 50 | inline friend typename boost::mpl::if_< | |
| 51 | boost::mpl::not_< boost::is_reference<reference> >, | |
| 52 | value_type, | |
| 53 | typename boost::mpl::if_< | |
| 54 | boost::is_const<reference>, | |
| 55 | reference, | |
| 56 | const value_type& | |
| 57 | >::type | |
| 58 | >::type | |
| 59 | get(const compose_property_map &m, const key_type &k) { | |
| 60 | return get(m.f, get(m.g, k)); | |
| 61 | } | |
| 62 | ||
| 63 | inline friend void | |
| 64 | put(const compose_property_map &m, const key_type &k, const value_type &v) { | |
| 65 | put(m.f, get(m.g, k), v); | |
| 66 | } | |
| 67 | ||
| 68 | private: | |
| 69 | FPMap f; | |
| 70 | GPMap g; | |
| 71 | }; | |
| 72 | ||
| 73 | template <class FPMap, class GPMap> | |
| 74 | inline compose_property_map<FPMap, GPMap> | |
| 75 | make_compose_property_map(const FPMap &f, const GPMap &g) { | |
| 76 | return compose_property_map<FPMap, GPMap>(f, g); | |
| 77 | } | |
| 78 | ||
| 79 | } // namespace boost | |
| 80 | ||
| 81 | #endif // BOOST_PROPERTY_MAP_COMPOSE_PROPERTY_MAP_HPP |