85 lines
3.7 KiB
Plaintext
85 lines
3.7 KiB
Plaintext
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// (C) Copyright John Maddock 2015.
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// Use, modification and distribution are subject to the Boost Software License,
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// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt).
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//
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// See http://www.boost.org/libs/type_traits for most recent version including documentation.
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#ifndef BOOST_TT_IS_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED
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#define BOOST_TT_IS_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED
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#include <cstddef> // size_t
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#include <boost/type_traits/integral_constant.hpp>
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#include <boost/detail/workaround.hpp>
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#if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700)
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#include <boost/type_traits/is_abstract.hpp>
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#endif
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#if !defined(BOOST_NO_CXX11_DECLTYPE) && !BOOST_WORKAROUND(BOOST_MSVC, < 1800) && !BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40500)
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#include <boost/type_traits/detail/yes_no_type.hpp>
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namespace boost{
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namespace detail{
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struct is_default_constructible_imp
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{
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template<typename _Tp, typename = decltype(_Tp())>
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static boost::type_traits::yes_type test(int);
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template<typename>
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static boost::type_traits::no_type test(...);
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};
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#if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700)
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template<class T, bool b>
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struct is_default_constructible_abstract_filter
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{
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static const bool value = sizeof(is_default_constructible_imp::test<T>(0)) == sizeof(boost::type_traits::yes_type);
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};
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template<class T>
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struct is_default_constructible_abstract_filter<T, true>
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{
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static const bool value = false;
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};
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#endif
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}
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#if BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40700)
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template <class T> struct is_default_constructible : public integral_constant<bool, detail::is_default_constructible_abstract_filter<T, boost::is_abstract<T>::value>::value>{};
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#else
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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)>{};
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#endif
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template <class T, std::size_t N> struct is_default_constructible<T[N]> : public is_default_constructible<T>{};
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template <class T> struct is_default_constructible<T[]> : public is_default_constructible<T>{};
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template <class T> struct is_default_constructible<T&> : public integral_constant<bool, false>{};
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#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
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template <class T> struct is_default_constructible<T&&> : public integral_constant<bool, false>{};
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#endif
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template <> struct is_default_constructible<void> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void const> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void volatile> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void const volatile> : public integral_constant<bool, false>{};
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#else
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#include <boost/type_traits/is_pod.hpp>
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namespace boost{
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// We don't know how to implement this, note we can not use has_trivial_constructor here
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// because the correct implementation of that trait requires this one:
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template <class T> struct is_default_constructible : public is_pod<T>{};
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template <> struct is_default_constructible<void> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void const> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void volatile> : public integral_constant<bool, false>{};
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template <> struct is_default_constructible<void const volatile> : public integral_constant<bool, false>{};
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#endif
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} // namespace boost
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#endif // BOOST_TT_IS_DEFAULT_CONSTRUCTIBLE_HPP_INCLUDED
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