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- // Boost.TypeErasure library
- //
- // Copyright 2011 Steven Watanabe
- //
- // 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)
- //
- // $Id$
- #ifndef BOOST_TYPE_ERASURE_BUILTIN_HPP_INCLUDED
- #define BOOST_TYPE_ERASURE_BUILTIN_HPP_INCLUDED
- #include <boost/mpl/vector.hpp>
- #include <boost/utility/enable_if.hpp>
- #include <boost/type_traits/is_reference.hpp>
- #include <boost/type_erasure/detail/storage.hpp>
- #include <boost/type_erasure/placeholder.hpp>
- #include <boost/type_erasure/constructible.hpp>
- #include <boost/type_erasure/rebind_any.hpp>
- #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
- # include <utility> // std::move
- #endif
- #include <typeinfo>
- namespace boost {
- namespace type_erasure {
- /**
- * The @ref destructible concept enables forwarding to
- * the destructor of the contained type. This is required
- * whenever an @ref any is created by value.
- *
- * \note The @ref destructible concept rarely needs to
- * be specified explicitly, because it is included in
- * the @ref copy_constructible concept.
- *
- * \note @ref destructible may not be specialized and
- * may not be passed to \call as it depends on the
- * implementation details of @ref any.
- */
- template<class T = _self>
- struct destructible
- {
- /** INTERNAL ONLY */
- typedef void (*type)(detail::storage&);
- /** INTERNAL ONLY */
- static void value(detail::storage& arg)
- {
- delete static_cast<T*>(arg.data);
- }
- /** INTERNAL ONLY */
- static void apply(detail::storage& arg)
- {
- delete static_cast<T*>(arg.data);
- }
- };
- /**
- * The @ref copy_constructible concept allows objects to
- * be copied and destroyed.
- *
- * \note This concept is defined to match C++ 2003,
- * [lib.copyconstructible]. It is not equivalent to
- * the concept of the same name in C++11.
- */
- template<class T = _self>
- struct copy_constructible :
- ::boost::mpl::vector<constructible<T(const T&)>, destructible<T> >
- {};
- #ifdef BOOST_TYPE_ERASURE_DOXYGEN
- /**
- * Enables assignment of @ref any types.
- */
- template<class T = _self, class U = const T&>
- struct assignable
- {
- static void apply(T& dst, U src);
- };
- #else
- /**
- * Enables assignment of @ref any types.
- */
- template<class T = _self, class U = const T&>
- struct assignable :
- ::boost::mpl::vector<assignable<T, const U&> >
- {};
- #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
- /** INTERNAL ONLY */
- template<class T, class U>
- struct assignable<T, U&&>
- {
- static void apply(T& dst, U&& src) { dst = std::forward<U>(src); }
- };
- #endif
- /** INTERNAL ONLY */
- template<class T, class U>
- struct assignable<T, U&>
- {
- static void apply(T& dst, U& src) { dst = src; }
- };
- /** INTERNAL ONLY */
- template<class T, class U, class Base>
- struct concept_interface<assignable<T, U>, Base, T,
- typename ::boost::enable_if_c< ::boost::is_reference<U>::value>::type> : Base
- {
- using Base::_boost_type_erasure_deduce_assign;
- assignable<T, U>* _boost_type_erasure_deduce_assign(
- typename ::boost::type_erasure::as_param<Base, U>::type)
- {
- return 0;
- }
- };
- #endif
- /**
- * Enables runtime type information. This is required
- * if you want to use \any_cast or \typeid_of.
- *
- * \note @ref typeid_ cannot be specialized because several
- * library components including \any_cast would not work
- * correctly if its behavior changed. There is no need
- * to specialize it anyway, since it works for all types.
- * @ref typeid_ also cannot be passed to \call. To access it,
- * use \typeid_of.
- */
- template<class T = _self>
- struct typeid_
- {
- /** INTERNAL ONLY */
- typedef const std::type_info& (*type)();
- /** INTERNAL ONLY */
- static const std::type_info& value()
- {
- return typeid(T);
- }
- /** INTERNAL ONLY */
- static const std::type_info& apply()
- {
- return typeid(T);
- }
- };
- namespace detail {
- template<class C>
- struct get_null_vtable_entry;
- template<class T>
- struct get_null_vtable_entry< ::boost::type_erasure::typeid_<T> >
- {
- typedef typeid_<void> type;
- };
- struct null_destroy {
- static void value(::boost::type_erasure::detail::storage&) {}
- };
- template<class T>
- struct get_null_vtable_entry< ::boost::type_erasure::destructible<T> >
- {
- typedef ::boost::type_erasure::detail::null_destroy type;
- };
- }
- }
- }
- #endif
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