91 lines
3.2 KiB
C++
91 lines
3.2 KiB
C++
|
///////////////////////////////////////////////////////////////////////////////
|
||
|
|
// 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/type_traits/is_convertible.hpp>
|
||
|
|
#include <boost/utility/declval.hpp>
|
||
|
|
|
||
|
|
|
||
|
|
namespace boost {
|
||
|
|
namespace multiprecision {
|
||
|
|
namespace detail {
|
||
|
|
|
||
|
|
template <int N>
|
||
|
|
struct dummy_size {};
|
||
|
|
|
||
|
|
template<typename S, typename T>
|
||
|
|
struct has_generic_interconversion
|
||
|
|
{
|
||
|
|
typedef typename mpl::if_c <
|
||
|
|
is_number<S>::value && is_number<T>::value,
|
||
|
|
typename mpl::if_c <
|
||
|
|
number_category<S>::value == number_kind_integer,
|
||
|
|
typename mpl::if_c<
|
||
|
|
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,
|
||
|
|
mpl::true_,
|
||
|
|
mpl::false_
|
||
|
|
>::type,
|
||
|
|
typename mpl::if_c<
|
||
|
|
number_category<S>::value == number_kind_rational,
|
||
|
|
typename mpl::if_c<
|
||
|
|
number_category<T>::value == number_kind_rational
|
||
|
|
|| number_category<T>::value == number_kind_rational,
|
||
|
|
mpl::true_,
|
||
|
|
mpl::false_
|
||
|
|
>::type,
|
||
|
|
typename mpl::if_c<
|
||
|
|
number_category<T>::value == number_kind_floating_point,
|
||
|
|
mpl::true_,
|
||
|
|
mpl::false_
|
||
|
|
>::type
|
||
|
|
>::type
|
||
|
|
> ::type,
|
||
|
|
mpl::false_
|
||
|
|
> ::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(static_cast<T1>(declval<S1>()))>*);
|
||
|
|
|
||
|
|
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 mpl::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
|
||
|
|
|
||
|
|
}}} // namespaces
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|