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- ///////////////////////////////////////////////////////////////////////////////
- // Copyright Vicente J. Botet Escriba 2009-2011
- // Copyright 2012 John Maddock. Distributed under the Boost
- // Software License, Version 1.0. (See accompanying file
- // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- #ifndef BOOST_MP_EXPLICIT_CONVERTIBLE_HPP
- #define BOOST_MP_EXPLICIT_CONVERTIBLE_HPP
- #include <boost/config.hpp>
- #include <boost/type_traits/conditional.hpp>
- #include <boost/type_traits/integral_constant.hpp>
- #include <boost/type_traits/is_convertible.hpp>
- #include <boost/type_traits/declval.hpp>
- #include <boost/multiprecision/detail/number_base.hpp> // number_category
- namespace boost {
- namespace multiprecision {
- namespace detail {
- template <unsigned int N>
- struct dummy_size
- {};
- template <typename S, typename T>
- struct has_generic_interconversion
- {
- typedef typename boost::conditional<
- is_number<S>::value && is_number<T>::value,
- typename boost::conditional<
- number_category<S>::value == number_kind_integer,
- typename boost::conditional<
- 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,
- boost::true_type,
- boost::false_type>::type,
- typename boost::conditional<
- number_category<S>::value == number_kind_rational,
- typename boost::conditional<
- number_category<T>::value == number_kind_rational || number_category<T>::value == number_kind_rational,
- boost::true_type,
- boost::false_type>::type,
- typename boost::conditional<
- number_category<T>::value == number_kind_floating_point,
- boost::true_type,
- boost::false_type>::type>::type>::type,
- boost::false_type>::type type;
- };
- template <typename S, typename T>
- struct is_explicitly_convertible_imp
- {
- #ifndef BOOST_NO_SFINAE_EXPR
- template <typename S1, typename T1>
- static type_traits::yes_type selector(dummy_size<sizeof(new T1(boost::declval<
- #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
- S1
- #else
- S1 const&
- #endif
- >()))>*);
- template <typename S1, typename T1>
- static type_traits::no_type selector(...);
- static const bool value = sizeof(selector<S, T>(0)) == sizeof(type_traits::yes_type);
- typedef boost::integral_constant<bool, value> type;
- #else
- typedef typename has_generic_interconversion<S, T>::type gen_type;
- typedef boost::integral_constant<bool, boost::is_convertible<S, T>::value || gen_type::value> type;
- #endif
- };
- template <typename From, typename To>
- struct is_explicitly_convertible : public is_explicitly_convertible_imp<From, To>::type
- {
- };
- #ifdef BOOST_NO_SFINAE_EXPR
- template <class Backend1, expression_template_option ExpressionTemplates1, class Backend2, expression_template_option ExpressionTemplates2>
- struct is_explicitly_convertible<number<Backend1, ExpressionTemplates1>, number<Backend2, ExpressionTemplates2> >
- : public is_explicitly_convertible<Backend1, Backend2>
- {
- };
- #endif
- }}} // namespace boost::multiprecision::detail
- #endif
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