text: 
  //  (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_CONSTRUCTIBLE_HPP_INCLUDED
  #define BOOST_TT_IS_CONSTRUCTIBLE_HPP_INCLUDED
  
  #include <boost/type_traits/integral_constant.hpp>
  #include <boost/detail/workaround.hpp>
  
  #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_DECLTYPE) && !BOOST_WORKAROUND(BOOST_MSVC, < 1800) && !BOOST_WORKAROUND(BOOST_GCC_VERSION, < 40500)
  
  #include <boost/type_traits/is_destructible.hpp>
  #include <boost/type_traits/is_default_constructible.hpp>
  #include <boost/type_traits/detail/yes_no_type.hpp>
  #include <boost/type_traits/declval.hpp>
  
  namespace mars_boost {} namespace boost = mars_boost; namespace mars_boost{
  
     namespace detail{
  
        struct is_constructible_imp
        {
           template<typename T, typename ...TheArgs, typename = decltype(T(mars_boost::declval<TheArgs>()...))>
           static mars_boost::type_traits::yes_type test(int);
           template<typename, typename...>
           static mars_boost::type_traits::no_type test(...);
  
           template<typename T, typename Arg, typename = decltype(::new T(mars_boost::declval<Arg>()))>
           static mars_boost::type_traits::yes_type test1(int);
           template<typename, typename>
           static mars_boost::type_traits::no_type test1(...);
  
           template <typename T>
           static mars_boost::type_traits::yes_type ref_test(T);
           template <typename T>
           static mars_boost::type_traits::no_type ref_test(...);
        };
  
     }
  
     template <class T, class ...Args> struct is_constructible : public integral_constant<bool, sizeof(detail::is_constructible_imp::test<T, Args...>(0)) == sizeof(mars_boost::type_traits::yes_type)>{};
     template <class T, class Arg> struct is_constructible<T, Arg> : public integral_constant<bool, is_destructible<T>::value && sizeof(detail::is_constructible_imp::test1<T, Arg>(0)) == sizeof(mars_boost::type_traits::yes_type)>{};
     template <class Ref, class Arg> struct is_constructible<Ref&, Arg> : public integral_constant<bool, sizeof(detail::is_constructible_imp::ref_test<Ref&>(mars_boost::declval<Arg>())) == sizeof(mars_boost::type_traits::yes_type)>{};
     template <class Ref, class Arg> struct is_constructible<Ref&&, Arg> : public integral_constant<bool, sizeof(detail::is_constructible_imp::ref_test<Ref&&>(mars_boost::declval<Arg>())) == sizeof(mars_boost::type_traits::yes_type)>{};
  
     template <> struct is_constructible<void> : public false_type{};
     template <> struct is_constructible<void const> : public false_type{};
     template <> struct is_constructible<void const volatile> : public false_type{};
     template <> struct is_constructible<void volatile> : public false_type{};
  
     template <class T> struct is_constructible<T> : public is_default_constructible<T>{};
  
  #else
  
  #include <boost/type_traits/is_convertible.hpp>
  #include <boost/type_traits/is_default_constructible.hpp>
  
  namespace mars_boost {} namespace boost = mars_boost; namespace mars_boost{
  
     // We don't know how to implement this:
     template <class T, class U = void> struct is_constructible : public is_convertible<U, T>{};
     template <class T> struct is_constructible<T, void> : public is_default_constructible<T>{};
     template <> struct is_constructible<void, void> : public false_type{};
     template <> struct is_constructible<void const, void> : public false_type{};
     template <> struct is_constructible<void const volatile, void> : public false_type{};
     template <> struct is_constructible<void volatile, void> : public false_type{};
     template <class Ref> struct is_constructible<Ref&, void> : public false_type{};
  #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
     template <class Ref> struct is_constructible<Ref&&, void> : public false_type{};
  #endif
  #endif
  
  } // namespace mars_boost
  
  #endif // BOOST_TT_IS_CONSTRUCTIBLE_HPP_INCLUDED
  