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1 | /////////////////////////////////////////////////////////////////////////////// |
2 | // Copyright Vicente J. Botet Escriba 2009-2011 | |
3 | // Copyright 2012 John Maddock. Distributed under the Boost | |
4 | // Software License, Version 1.0. (See accompanying file | |
5 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
6 | ||
7 | #ifndef BOOST_MP_EXPLICIT_CONVERTIBLE_HPP | |
8 | #define BOOST_MP_EXPLICIT_CONVERTIBLE_HPP | |
9 | ||
92f5a8d4 TL |
10 | #include <boost/config.hpp> |
11 | #include <boost/type_traits/conditional.hpp> | |
12 | #include <boost/type_traits/integral_constant.hpp> | |
7c673cae | 13 | #include <boost/type_traits/is_convertible.hpp> |
92f5a8d4 TL |
14 | #include <boost/type_traits/declval.hpp> |
15 | #include <boost/multiprecision/detail/number_base.hpp> // number_category | |
7c673cae FG |
16 | |
17 | namespace boost { | |
92f5a8d4 TL |
18 | namespace multiprecision { |
19 | namespace detail { | |
7c673cae | 20 | |
92f5a8d4 TL |
21 | template <unsigned int N> |
22 | struct dummy_size | |
23 | {}; | |
7c673cae | 24 | |
92f5a8d4 TL |
25 | template <typename S, typename T> |
26 | struct has_generic_interconversion | |
27 | { | |
28 | typedef typename boost::conditional< | |
29 | is_number<S>::value && is_number<T>::value, | |
30 | typename boost::conditional< | |
31 | number_category<S>::value == number_kind_integer, | |
32 | typename boost::conditional< | |
33 | number_category<T>::value == number_kind_integer || number_category<T>::value == number_kind_floating_point || number_category<T>::value == number_kind_rational || number_category<T>::value == number_kind_fixed_point, | |
34 | boost::true_type, | |
35 | boost::false_type>::type, | |
36 | typename boost::conditional< | |
7c673cae | 37 | number_category<S>::value == number_kind_rational, |
92f5a8d4 TL |
38 | typename boost::conditional< |
39 | number_category<T>::value == number_kind_rational || number_category<T>::value == number_kind_rational, | |
40 | boost::true_type, | |
41 | boost::false_type>::type, | |
42 | typename boost::conditional< | |
43 | number_category<T>::value == number_kind_floating_point, | |
44 | boost::true_type, | |
45 | boost::false_type>::type>::type>::type, | |
46 | boost::false_type>::type type; | |
47 | }; | |
7c673cae | 48 | |
92f5a8d4 TL |
49 | template <typename S, typename T> |
50 | struct is_explicitly_convertible_imp | |
51 | { | |
7c673cae | 52 | #ifndef BOOST_NO_SFINAE_EXPR |
92f5a8d4 TL |
53 | template <typename S1, typename T1> |
54 | static type_traits::yes_type selector(dummy_size<sizeof(new T1(boost::declval< | |
55 | #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) | |
56 | S1 | |
57 | #else | |
58 | S1 const& | |
59 | #endif | |
60 | >()))>*); | |
7c673cae | 61 | |
92f5a8d4 TL |
62 | template <typename S1, typename T1> |
63 | static type_traits::no_type selector(...); | |
7c673cae | 64 | |
92f5a8d4 | 65 | static const bool value = sizeof(selector<S, T>(0)) == sizeof(type_traits::yes_type); |
7c673cae | 66 | |
92f5a8d4 | 67 | typedef boost::integral_constant<bool, value> type; |
7c673cae | 68 | #else |
92f5a8d4 TL |
69 | typedef typename has_generic_interconversion<S, T>::type gen_type; |
70 | typedef boost::integral_constant<bool, boost::is_convertible<S, T>::value || gen_type::value> type; | |
7c673cae | 71 | #endif |
92f5a8d4 | 72 | }; |
7c673cae | 73 | |
92f5a8d4 | 74 | template <typename From, typename To> |
7c673cae FG |
75 | struct is_explicitly_convertible : public is_explicitly_convertible_imp<From, To>::type |
76 | { | |
77 | }; | |
78 | ||
79 | #ifdef BOOST_NO_SFINAE_EXPR | |
92f5a8d4 | 80 | template <class Backend1, expression_template_option ExpressionTemplates1, class Backend2, expression_template_option ExpressionTemplates2> |
7c673cae | 81 | struct is_explicitly_convertible<number<Backend1, ExpressionTemplates1>, number<Backend2, ExpressionTemplates2> > |
92f5a8d4 | 82 | : public is_explicitly_convertible<Backend1, Backend2> |
7c673cae FG |
83 | { |
84 | }; | |
85 | #endif | |
86 | ||
92f5a8d4 | 87 | }}} // namespace boost::multiprecision::detail |
7c673cae FG |
88 | |
89 | #endif |