| |
| // (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_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED |
| #define BOOST_TT_IS_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED |
| |
| #include <cstddef> // size_t |
| #include <boost/type_traits/integral_constant.hpp> |
| #include <boost/detail/workaround.hpp> |
| |
| #if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700) |
| #include <boost/type_traits/is_abstract.hpp> |
| #endif |
| |
| #if !defined(BOOST_NO_CXX11_DECLTYPE) && !BOOST_WORKAROUND(BOOST_MSVC, < 1800) && !BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40500) |
| |
| #include <boost/type_traits/detail/yes_no_type.hpp> |
| |
| namespace boost{ |
| |
| namespace detail{ |
| |
| struct is_default_constructible_imp |
| { |
| template<typename _Tp, typename = decltype(_Tp())> |
| static boost::type_traits::yes_type test(int); |
| |
| template<typename> |
| static boost::type_traits::no_type test(...); |
| }; |
| #if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700) |
| template<class T, bool b> |
| struct is_default_constructible_abstract_filter |
| { |
| static const bool value = sizeof(is_default_constructible_imp::test<T>(0)) == sizeof(boost::type_traits::yes_type); |
| }; |
| template<class T> |
| struct is_default_constructible_abstract_filter<T, true> |
| { |
| static const bool value = false; |
| }; |
| #endif |
| } |
| |
| #if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700) |
| template <class T> struct is_default_constructible : public integral_constant<bool, detail::is_default_constructible_abstract_filter<T, boost::is_abstract<T>::value>::value>{}; |
| #else |
| template <class T> struct is_default_constructible : public integral_constant<bool, sizeof(detail::is_default_constructible_imp::test<T>(0)) == sizeof(boost::type_traits::yes_type)>{}; |
| #endif |
| template <class T, std::size_t N> struct is_default_constructible<T[N]> : public is_default_constructible<T>{}; |
| template <class T> struct is_default_constructible<T[]> : public is_default_constructible<T>{}; |
| template <class T> struct is_default_constructible<T&> : public integral_constant<bool, false>{}; |
| #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) |
| template <class T> struct is_default_constructible<T&&> : public integral_constant<bool, false>{}; |
| #endif |
| template <> struct is_default_constructible<void> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void const> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void volatile> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void const volatile> : public integral_constant<bool, false>{}; |
| |
| #else |
| |
| #include <boost/type_traits/is_pod.hpp> |
| |
| namespace boost{ |
| |
| // We don't know how to implement this, note we can not use has_trivial_constructor here |
| // because the correct implementation of that trait requires this one: |
| template <class T> struct is_default_constructible : public is_pod<T>{}; |
| template <> struct is_default_constructible<void> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void const> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void volatile> : public integral_constant<bool, false>{}; |
| template <> struct is_default_constructible<void const volatile> : public integral_constant<bool, false>{}; |
| |
| #endif |
| |
| } // namespace boost |
| |
| #endif // BOOST_TT_IS_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED |