boost/type_erasure/constructible.hpp
// 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)
//
// $Id$
#if !defined(BOOST_PP_IS_ITERATING)
#ifndef BOOST_TYPE_ERASURE_CONSTRUCTIBLE_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_CONSTRUCTIBLE_HPP_INCLUDED
#include <boost/detail/workaround.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/enum_binary_params.hpp>
#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
#include <boost/type_erasure/detail/storage.hpp>
#include <boost/type_erasure/call.hpp>
#include <boost/type_erasure/concept_interface.hpp>
#include <boost/type_erasure/config.hpp>
#include <boost/type_erasure/param.hpp>
namespace boost {
namespace type_erasure {
template<class Sig>
struct constructible;
namespace detail {
template<class Sig>
struct null_construct;
template<class C>
struct get_null_vtable_entry;
template<class C, class Sig>
struct vtable_adapter;
}
#ifdef BOOST_TYPE_ERASURE_DOXYGEN
/**
* The @ref constructible concept enables calling the
* constructor of a type contained by an @ref any.
* @c Sig should be a function signature. The return
* type is the placeholder specifying the type to
* be constructed. The arguments are the argument
* types of the constructor. The arguments of
* @c Sig may be placeholders.
*
* \note @ref constructible may not be specialized and
* may not be passed to \call as it depends on the
* implementation details of @ref any.
*/
template<class Sig>
struct constructible {};
#elif !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
!defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
!BOOST_WORKAROUND(BOOST_MSVC, == 1800)
template<class R, class... T>
struct constructible<R(T...)>
{
static ::boost::type_erasure::detail::storage
apply(T... arg)
{
::boost::type_erasure::detail::storage result;
result.data = new R(::std::forward<T>(arg)...);
return result;
}
};
/// INTERNAL ONLY
template<class Base, class Tag, class... T>
struct concept_interface<
::boost::type_erasure::constructible<Tag(T...)>,
Base,
Tag
> : Base
{
using Base::_boost_type_erasure_deduce_constructor;
::boost::type_erasure::constructible<Tag(T...)>*
_boost_type_erasure_deduce_constructor(
typename ::boost::type_erasure::as_param<Base, T>::type...) const
{
return 0;
}
};
namespace detail {
template<class... T>
struct null_construct<void(T...)>
{
static ::boost::type_erasure::detail::storage
value(T...)
{
::boost::type_erasure::detail::storage result;
result.data = 0;
return result;
}
};
template<class T, class R, class... U>
struct get_null_vtable_entry<vtable_adapter<constructible<T(const T&)>, R(U...)> >
{
typedef null_construct<void(U...)> type;
};
}
#else
#define BOOST_PP_FILENAME_1 <boost/type_erasure/constructible.hpp>
#define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
#include BOOST_PP_ITERATE()
#endif
}
}
#endif
#else
#define N BOOST_PP_ITERATION()
#define BOOST_TYPE_ERASURE_ARG_DECL(z, n, data) \
typename ::boost::type_erasure::as_param< \
Base, \
BOOST_PP_CAT(T, n) \
>::type
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
#define BOOST_TYPE_ERASURE_FORWARD_I(z, n, data) ::std::forward<BOOST_PP_CAT(T, n)>(BOOST_PP_CAT(arg, n))
#define BOOST_TYPE_ERASURE_FORWARD(n) BOOST_PP_ENUM(n, BOOST_TYPE_ERASURE_FORWARD_I, ~)
#else
#define BOOST_TYPE_ERASURE_FORWARD(n) BOOST_PP_ENUM_PARAMS(n, arg)
#endif
template<class R BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
struct constructible<R(BOOST_PP_ENUM_PARAMS(N, T))>
{
static ::boost::type_erasure::detail::storage
apply(BOOST_PP_ENUM_BINARY_PARAMS(N, T, arg))
{
::boost::type_erasure::detail::storage result;
result.data = new R(BOOST_TYPE_ERASURE_FORWARD(N));
return result;
}
};
template<class Base BOOST_PP_ENUM_TRAILING_PARAMS(N, class T), class Tag>
struct concept_interface<
::boost::type_erasure::constructible<Tag(BOOST_PP_ENUM_PARAMS(N, T))>,
Base,
Tag
> : Base
{
using Base::_boost_type_erasure_deduce_constructor;
::boost::type_erasure::constructible<Tag(BOOST_PP_ENUM_PARAMS(N, T))>*
_boost_type_erasure_deduce_constructor(
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_ARG_DECL, ~)) const
{
return 0;
}
};
namespace detail {
template<BOOST_PP_ENUM_PARAMS(N, class T)>
struct null_construct<void(BOOST_PP_ENUM_PARAMS(N, T))>
{
static ::boost::type_erasure::detail::storage
value(BOOST_PP_ENUM_PARAMS(N, T))
{
::boost::type_erasure::detail::storage result;
result.data = 0;
return result;
}
};
template<class T, class R BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
struct get_null_vtable_entry<vtable_adapter<constructible<T(const T&)>, R(BOOST_PP_ENUM_PARAMS(N, T))> >
{
typedef null_construct<void(BOOST_PP_ENUM_PARAMS(N, T))> type;
};
}
#undef BOOST_TYPE_ERASURE_FORWARD
#undef BOOST_TYPE_ERASURE_FORWARD_I
#undef BOOST_TYPE_ERASURE_ARG_DECL
#undef N
#endif