78 lines
3.6 KiB
Plaintext
78 lines
3.6 KiB
Plaintext
|
|
||
|
|
// (C) Copyright John Maddock 2015.
|
||
|
|
// Use, modification and distribution are subject to 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).
|
||
|
|
//
|
||
|
|
// See http://www.boost.org/libs/type_traits for most recent version including documentation.
|
||
|
|
|
||
|
|
#ifndef BOOST_TT_IS_ASSIGNABLE_HPP_INCLUDED
|
||
|
|
#define BOOST_TT_IS_ASSIGNABLE_HPP_INCLUDED
|
||
|
|
|
||
|
|
#include <cstddef> // size_t
|
||
|
|
#include <boost/type_traits/integral_constant.hpp>
|
||
|
|
#include <boost/detail/workaround.hpp>
|
||
|
|
|
||
|
|
namespace boost{
|
||
|
|
|
||
|
|
template <class T, class U = T> struct is_assignable;
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
#if !defined(BOOST_NO_CXX11_DECLTYPE) && !BOOST_WORKAROUND(BOOST_MSVC, < 1800)
|
||
|
|
|
||
|
|
#include <boost/type_traits/detail/yes_no_type.hpp>
|
||
|
|
#include <boost/type_traits/declval.hpp>
|
||
|
|
|
||
|
|
namespace boost{
|
||
|
|
|
||
|
|
namespace detail{
|
||
|
|
|
||
|
|
struct is_assignable_imp
|
||
|
|
{
|
||
|
|
template<typename T, typename U, typename = decltype(boost::declval<T>() = boost::declval<U>())>
|
||
|
|
static boost::type_traits::yes_type test(int);
|
||
|
|
|
||
|
|
template<typename, typename>
|
||
|
|
static boost::type_traits::no_type test(...);
|
||
|
|
};
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class T, class U> struct is_assignable : public integral_constant<bool, sizeof(detail::is_assignable_imp::test<T, U>(0)) == sizeof(boost::type_traits::yes_type)>{};
|
||
|
|
template <class T, std::size_t N, class U> struct is_assignable<T[N], U> : public is_assignable<T, U>{};
|
||
|
|
template <class T, std::size_t N, class U> struct is_assignable<T(&)[N], U> : public is_assignable<T&, U>{};
|
||
|
|
template <class T, class U> struct is_assignable<T[], U> : public is_assignable<T, U>{};
|
||
|
|
template <class T, class U> struct is_assignable<T(&)[], U> : public is_assignable<T&, U>{};
|
||
|
|
template <class U> struct is_assignable<void, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void const, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void volatile, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void const volatile, U> : public integral_constant<bool, false>{};
|
||
|
|
|
||
|
|
#else
|
||
|
|
|
||
|
|
#include <boost/type_traits/has_trivial_assign.hpp>
|
||
|
|
#include <boost/type_traits/remove_reference.hpp>
|
||
|
|
|
||
|
|
namespace boost{
|
||
|
|
|
||
|
|
// We don't know how to implement this:
|
||
|
|
template <class T, class U> struct is_assignable : public integral_constant<bool, false>{};
|
||
|
|
template <class T, class U> struct is_assignable<T&, U> : public integral_constant<bool, is_pod<T>::value && is_pod<typename remove_reference<U>::type>::value>{};
|
||
|
|
template <class T, class U> struct is_assignable<const T&, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void const, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void volatile, U> : public integral_constant<bool, false>{};
|
||
|
|
template <class U> struct is_assignable<void const volatile, U> : public integral_constant<bool, false>{};
|
||
|
|
/*
|
||
|
|
template <> struct is_assignable<void, void> : public integral_constant<bool, false>{};
|
||
|
|
template <> struct is_assignable<void const, void const> : public integral_constant<bool, false>{};
|
||
|
|
template <> struct is_assignable<void volatile, void volatile> : public integral_constant<bool, false>{};
|
||
|
|
template <> struct is_assignable<void const volatile, void const volatile> : public integral_constant<bool, false>{};
|
||
|
|
*/
|
||
|
|
#endif
|
||
|
|
|
||
|
|
} // namespace boost
|
||
|
|
|
||
|
|
#endif // BOOST_TT_IS_ASSIGNABLE_HPP_INCLUDED
|