projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*-----------------------------------------------------------------------------+ |
| 2 | Copyright (c) 2008-2009: Joachim Faulhaber | |
| 3 | +------------------------------------------------------------------------------+ | |
| 4 | Distributed under the Boost Software License, Version 1.0. | |
| 5 | (See accompanying file LICENCE.txt or copy at | |
| 6 | http://www.boost.org/LICENSE_1_0.txt) | |
| 7 | +-----------------------------------------------------------------------------*/ | |
| 8 | #ifndef BOOST_ICL_TYPE_TRAITS_DIFFERENCE_TYPE_OF_HPP_JOFA_080911 | |
| 9 | #define BOOST_ICL_TYPE_TRAITS_DIFFERENCE_TYPE_OF_HPP_JOFA_080911 | |
| 10 | ||
| 11 | #include <boost/config.hpp> // For macro BOOST_STATIC_CONSTANT | |
| 12 | #include <boost/type_traits/is_pointer.hpp> | |
| 13 | #include <boost/mpl/has_xxx.hpp> | |
| 14 | #include <boost/mpl/or.hpp> | |
| 15 | #include <boost/mpl/and.hpp> | |
| 16 | #include <boost/mpl/not.hpp> | |
| 17 | #include <boost/icl/type_traits/no_type.hpp> | |
| 18 | #include <boost/icl/type_traits/is_numeric.hpp> | |
| 19 | #include <boost/icl/type_traits/rep_type_of.hpp> | |
| 20 | ||
| 21 | namespace boost{ namespace icl | |
| 22 | { | |
| 23 | namespace detail | |
| 24 | { | |
| 25 | BOOST_MPL_HAS_XXX_TRAIT_DEF(difference_type) | |
| 26 | } | |
| 27 | ||
| 28 | //-------------------------------------------------------------------------- | |
| 29 | template <class Type> | |
| 30 | struct has_difference_type | |
| 31 | : mpl::bool_<detail::has_difference_type<Type>::value> | |
| 32 | {}; | |
| 33 | ||
| 34 | //-------------------------------------------------------------------------- | |
| 35 | template<class Type> // type_of(T-T)==T | |
| 36 | struct is_subtraction_closed | |
| 37 | { | |
| 38 | typedef is_subtraction_closed type; | |
| 39 | BOOST_STATIC_CONSTANT(bool, | |
| 40 | value = (mpl::or_< is_numeric<Type> | |
| 41 | , mpl::and_< has_rep_type<Type> | |
| 42 | , mpl::not_<has_difference_type<Type> > | |
| 43 | > | |
| 44 | >::value) | |
| 45 | ); | |
| 46 | }; | |
| 47 | ||
| 48 | //-------------------------------------------------------------------------- | |
| 49 | template<class Type> | |
| 50 | struct has_difference | |
| 51 | { | |
| 52 | typedef has_difference type; | |
| 53 | BOOST_STATIC_CONSTANT(bool, | |
| 54 | value = (mpl::or_< is_subtraction_closed<Type> | |
| 55 | , is_pointer<Type> | |
| 56 | , has_difference_type<Type> >::value) | |
| 57 | ); | |
| 58 | }; | |
| 59 | ||
| 60 | //-------------------------------------------------------------------------- | |
| 61 | template <class Type, bool has_difference, bool has_diff_type> | |
| 62 | struct get_difference_type; | |
| 63 | ||
| 64 | template <class Type> | |
| 65 | struct get_difference_type<Type, false, false> | |
| 66 | { | |
| 67 | typedef no_type type; | |
| 68 | }; | |
| 69 | ||
| 70 | template <class Type> | |
| 71 | struct get_difference_type<Type*, true, false> | |
| 72 | { | |
| 73 | typedef std::ptrdiff_t type; | |
| 74 | }; | |
| 75 | ||
| 76 | template <class Type> | |
| 77 | struct get_difference_type<Type, true, false> | |
| 78 | { | |
| 79 | typedef Type type; | |
| 80 | }; | |
| 81 | ||
| 82 | template <class Type> | |
| 83 | struct get_difference_type<Type, true, true> | |
| 84 | { | |
| 85 | typedef typename Type::difference_type type; | |
| 86 | }; | |
| 87 | ||
| 88 | //-------------------------------------------------------------------------- | |
| 89 | template<class Type> | |
| 90 | struct difference_type_of | |
| 91 | { | |
| 92 | typedef typename | |
| 93 | get_difference_type< Type | |
| 94 | , has_difference<Type>::value | |
| 95 | , has_difference_type<Type>::value | |
| 96 | >::type type; | |
| 97 | }; | |
| 98 | ||
| 99 | }} // namespace boost icl | |
| 100 | ||
| 101 | #endif | |
| 102 | ||
| 103 |