boost/type_erasure/call.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_CALL_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_CALL_HPP_INCLUDED
#include <boost/assert.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/inc.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/repetition/repeat.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_trailing.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/preprocessor/repetition/enum_trailing_binary_params.hpp>
#include <boost/type_erasure/detail/access.hpp>
#include <boost/type_erasure/detail/adapt_to_vtable.hpp>
#include <boost/type_erasure/detail/extract_concept.hpp>
#include <boost/type_erasure/detail/get_signature.hpp>
#include <boost/type_erasure/detail/check_call.hpp>
#include <boost/type_erasure/is_placeholder.hpp>
#include <boost/type_erasure/concept_of.hpp>
#include <boost/type_erasure/config.hpp>
#include <boost/type_erasure/require_match.hpp>
namespace boost {
namespace type_erasure {
template<class Concept, class Placeholder>
class any;
template<class Concept>
class binding;
namespace detail {
template<class T>
struct is_placeholder_arg :
::boost::type_erasure::is_placeholder<
typename ::boost::remove_cv<
typename ::boost::remove_reference<T>::type
>::type
>
{};
template<class T, class Table>
int maybe_get_table(const T& arg, const Table*& table, boost::mpl::true_)
{
if(table == 0) {
table = &::boost::type_erasure::detail::access::table(arg);
}
return 0;
}
template<class T, class Table>
int maybe_get_table(const T&, const Table*&, boost::mpl::false_) { return 0; }
template<class T>
::boost::type_erasure::detail::storage& convert_arg(any_base<T>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(any_base<any<Concept, const T&> >& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class T>
const ::boost::type_erasure::detail::storage&
convert_arg(const any_base<T>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&
convert_arg(const any_base<any<Concept, T&> >& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(const any_base<any<Concept, const T&> >& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&
convert_arg(param<Concept, T>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(param<Concept, const T&>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(const param<Concept, T>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(any_base<any<Concept, const T&> >&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&
convert_arg(any_base<any<Concept, T&> >&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(any_base<any<Concept, T> >&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(std::move(arg));
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(any_base<any<Concept, T&&> >& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(const any_base<any<Concept, T&&> >& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
const ::boost::type_erasure::detail::storage&
convert_arg(param<Concept, const T&>&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&
convert_arg(param<Concept, T&>&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(param<Concept, T>&& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(std::move(arg));
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(param<Concept, T&&>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class Concept, class T>
::boost::type_erasure::detail::storage&&
convert_arg(const param<Concept, T&&>& arg, boost::mpl::true_)
{
return ::boost::type_erasure::detail::access::data(arg);
}
template<class T>
T&& convert_arg(T&& arg, boost::mpl::false_) { return std::forward<T>(arg); }
#else
template<class T>
T& convert_arg(T& arg, boost::mpl::false_) { return arg; }
#endif
}
#ifdef BOOST_TYPE_ERASURE_DOXYGEN
/**
* Dispatches a type erased function.
*
* @c Op must be a primitive concept which is present in
* @c Concept. Its signature determines how the arguments of
* \call are handled. If the argument is a @ref placeholder,
* \call expects an @ref any using that @ref placeholder.
* This @ref any is unwrapped by \call. The type that
* it stores must be the same type specified by @c binding.
* Any arguments that are not placeholders in the signature
* of @c Op are passed through unchanged.
*
* If @c binding is not specified, it will be deduced from
* the arguments. Naturally this requires at least one
* argument to be an @ref any. In this case, all @ref any
* arguments must have the same @ref binding.
*
* \return The result of the operation. If the result type
* of the signature of @c Op is a placeholder, the
* result will be converted to the appropriate @ref
* any type.
*
* \throws bad_function_call if @ref relaxed is
* in @c Concept and there is a type mismatch.
*
* Example:
*
* @code
* typedef mpl::vector<
* copy_constructible<_b>,
* addable<_a, int, _b> > concept;
* any<concept, _a> a = ...;
* any<concept, _b> b(call(addable<_a, int, _b>(), a, 10));
* @endcode
*
* The signature of @ref addable is <code>_b(const _a&, const int&)</code>
*/
template<class Concept, class Op, class... U>
typename ::boost::type_erasure::detail::call_impl<Sig, U..., Concept>::type
call(const binding<Concept>& binding_arg, const Op&, U&&... args);
/**
* \overload
*/
template<class Op, class... U>
typename ::boost::type_erasure::detail::call_impl<Sig, U...>::type
call(const Op&, U&&... args);
#else
namespace detail {
template<class Sig, class Args, class Concept = void,
bool Check = ::boost::type_erasure::detail::check_call<Sig, Args>::type::value>
struct call_impl {};
template<class Op, class Args, class Concept = void>
struct call_result :
call_impl<
typename ::boost::type_erasure::detail::get_signature<Op>::type,
Args,
Concept>
{};
template<class C1, class Args, class Concept>
struct call_result<
::boost::type_erasure::binding<C1>,
Args,
Concept
>
{};
}
#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
namespace detail {
template<class... T>
void ignore(const T&...) {}
template<class R, class... T, class... U>
const ::boost::type_erasure::binding<
typename ::boost::type_erasure::detail::extract_concept<void(T...), U...>::type>*
extract_table(R(*)(T...), const U&... arg)
{
const ::boost::type_erasure::binding<
typename ::boost::type_erasure::detail::extract_concept<
void(T...), U...>::type>* result = 0;
// the order that we run maybe_get_table in doesn't matter
ignore(::boost::type_erasure::detail::maybe_get_table(
arg,
result,
::boost::type_erasure::detail::is_placeholder_arg<T>())...);
BOOST_ASSERT(result != 0);
return result;
}
template<class Sig, class Args, class Concept, bool ReturnsAny>
struct call_impl_dispatch;
template<class R, class... T, class... U, class Concept>
struct call_impl_dispatch<R(T...), void(U...), Concept, false>
{
typedef R type;
template<class F>
static R apply(const ::boost::type_erasure::binding<Concept>* table, U... arg)
{
return table->template find<F>()(
::boost::type_erasure::detail::convert_arg(
::std::forward<U>(arg),
::boost::type_erasure::detail::is_placeholder_arg<T>())...);
}
};
template<class R, class... T, class... U, class Concept>
struct call_impl_dispatch<R(T...), void(U...), Concept, true>
{
typedef ::boost::type_erasure::any<Concept, R> type;
template<class F>
static type apply(const ::boost::type_erasure::binding<Concept>* table, U... arg)
{
return type(table->template find<F>()(
::boost::type_erasure::detail::convert_arg(
::std::forward<U>(arg),
::boost::type_erasure::detail::is_placeholder_arg<T>())...), *table);
}
};
template<class R, class... T, class... U, class Concept>
struct call_impl<R(T...), void(U...), Concept, true> :
::boost::type_erasure::detail::call_impl_dispatch<
R(T...),
void(U...),
Concept,
::boost::type_erasure::detail::is_placeholder_arg<R>::value
>
{
};
template<class R, class... T, class... U>
struct call_impl<R(T...), void(U...), void, true> :
::boost::type_erasure::detail::call_impl_dispatch<
R(T...),
void(U...),
typename ::boost::type_erasure::detail::extract_concept<
void(T...),
typename ::boost::remove_reference<U>::type...
>::type,
::boost::type_erasure::detail::is_placeholder_arg<R>::value
>
{
};
}
template<
class Concept,
class Op,
class... U
>
typename ::boost::type_erasure::detail::call_result<
Op,
void(U&&...),
Concept
>::type
unchecked_call(
const ::boost::type_erasure::binding<Concept>& table,
const Op&,
U&&... arg)
{
return ::boost::type_erasure::detail::call_impl<
typename ::boost::type_erasure::detail::get_signature<Op>::type,
void(U&&...),
Concept
>::template apply<
typename ::boost::type_erasure::detail::adapt_to_vtable<Op>::type
>(&table, std::forward<U>(arg)...);
}
template<class Concept, class Op, class... U>
typename ::boost::type_erasure::detail::call_result<
Op,
void(U&&...),
Concept
>::type
call(
const ::boost::type_erasure::binding<Concept>& table,
const Op& f,
U&&... arg)
{
::boost::type_erasure::require_match(table, f, std::forward<U>(arg)...);
return ::boost::type_erasure::unchecked_call(table, f, std::forward<U>(arg)...);
}
template<class Op, class... U>
typename ::boost::type_erasure::detail::call_result<
Op,
void(U&&...)
>::type
unchecked_call(
const Op&,
U&&... arg)
{
return ::boost::type_erasure::detail::call_impl<
typename ::boost::type_erasure::detail::get_signature<Op>::type,
void(U&&...)
>::template apply<
typename ::boost::type_erasure::detail::adapt_to_vtable<Op>::type
>(::boost::type_erasure::detail::extract_table(
static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0), arg...),
std::forward<U>(arg)...);
}
template<class Op, class... U>
typename ::boost::type_erasure::detail::call_result<
Op,
void(U&&...)
>::type
call(
const Op& f,
U&&... arg)
{
::boost::type_erasure::require_match(f, std::forward<U>(arg)...);
return ::boost::type_erasure::unchecked_call(f, std::forward<U>(arg)...);
}
#else
#define BOOST_PP_FILENAME_1 <boost/type_erasure/call.hpp>
#define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
#include BOOST_PP_ITERATE()
#endif
#endif
}
}
#endif
#else
#define N BOOST_PP_ITERATION()
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
#define BOOST_TYPE_ERASURE_CONVERT_ARG(z, n, data) \
::boost::type_erasure::detail::convert_arg( \
std::forward<BOOST_PP_CAT(U, n)>(BOOST_PP_CAT(arg, n)), \
::boost::type_erasure::detail::is_placeholder_arg<BOOST_PP_CAT(T, n)>())
#else
#define BOOST_TYPE_ERASURE_CONVERT_ARG(z, n, data) \
::boost::type_erasure::detail::convert_arg( \
BOOST_PP_CAT(arg, n), \
::boost::type_erasure::detail::is_placeholder_arg<BOOST_PP_CAT(T, n)>())
#endif
#define BOOST_TYPE_ERASURE_GET_TABLE(z, n, data) \
::boost::type_erasure::detail::maybe_get_table( \
BOOST_PP_CAT(arg, n), \
result, \
::boost::type_erasure::detail::is_placeholder_arg<BOOST_PP_CAT(T, n)>());
namespace detail {
#if N != 0
template<
class R,
BOOST_PP_ENUM_PARAMS(N, class T),
BOOST_PP_ENUM_PARAMS(N, class U)>
const ::boost::type_erasure::binding<
typename ::boost::type_erasure::detail::BOOST_PP_CAT(extract_concept, N)<
BOOST_PP_ENUM_PARAMS(N, T),
BOOST_PP_ENUM_PARAMS(N, U)>::type>*
BOOST_PP_CAT(extract_table, N)(R(*)(BOOST_PP_ENUM_PARAMS(N, T)), BOOST_PP_ENUM_BINARY_PARAMS(N, const U, &arg))
{
const ::boost::type_erasure::binding<
typename ::boost::type_erasure::detail::BOOST_PP_CAT(extract_concept, N)<
BOOST_PP_ENUM_PARAMS(N, T),
BOOST_PP_ENUM_PARAMS(N, U)>::type>* result = 0;
BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_GET_TABLE, ~)
BOOST_ASSERT(result != 0);
return result;
}
#endif
template<
class R
BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U),
class Concept
#if N != 0
= typename ::boost::type_erasure::detail::BOOST_PP_CAT(extract_concept, N)<
BOOST_PP_ENUM_PARAMS(N, T),
BOOST_PP_ENUM_PARAMS(N, U)
>::type
#endif
,
bool ReturnsAny = ::boost::type_erasure::detail::is_placeholder_arg<R>::value>
struct BOOST_PP_CAT(call_impl, N);
template<
class R
BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U),
class Concept
>
struct BOOST_PP_CAT(call_impl, N)<
R
BOOST_PP_ENUM_TRAILING_PARAMS(N, T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, U),
Concept,
false
>
{
typedef R type;
template<class F>
static R apply(const ::boost::type_erasure::binding<Concept>* table
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, arg))
{
return table->template find<F>()(
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_CONVERT_ARG, ~));
}
};
template<
class R
BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U),
class Concept
>
struct BOOST_PP_CAT(call_impl, N)<
R
BOOST_PP_ENUM_TRAILING_PARAMS(N, T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, U),
Concept,
true
>
{
typedef ::boost::type_erasure::any<Concept, R> type;
template<class F>
static type apply(const ::boost::type_erasure::binding<Concept>* table
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, arg))
{
return type(table->template find<F>()(
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_CONVERT_ARG, ~)), *table);
}
};
template<
class R
BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U),
class Concept
>
struct call_impl<R(BOOST_PP_ENUM_PARAMS(N, T)), void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, u)), Concept, true>
: BOOST_PP_CAT(call_impl, N)<R BOOST_PP_ENUM_TRAILING_PARAMS(N, T) BOOST_PP_ENUM_TRAILING_PARAMS(N, U), Concept>
{};
#if N != 0
template<
class R
BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
>
struct call_impl<R(BOOST_PP_ENUM_PARAMS(N, T)), void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, u)), void, true>
: BOOST_PP_CAT(call_impl, N)<R BOOST_PP_ENUM_TRAILING_PARAMS(N, T) BOOST_PP_ENUM_TRAILING_PARAMS(N, U)>
{};
#endif
}
#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
#define RREF &
#define BOOST_TYPE_ERASURE_FORWARD_ARGS(N, X, x) BOOST_PP_ENUM_TRAILING_PARAMS(N, x)
#else
#define RREF &&
#define BOOST_TYPE_ERASURE_FORWARD_ARGS_I(z, n, data) std::forward<BOOST_PP_CAT(BOOST_PP_TUPLE_ELEM(2, 0, data), n)>(BOOST_PP_CAT(BOOST_PP_TUPLE_ELEM(2, 1, data), n))
#define BOOST_TYPE_ERASURE_FORWARD_ARGS(N, X, x) BOOST_PP_ENUM_TRAILING(N, BOOST_TYPE_ERASURE_FORWARD_ARGS_I, (X, x))
#endif
template<
class Concept,
class Op
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
>
typename ::boost::type_erasure::detail::call_result<
Op,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u)),
Concept
>::type
unchecked_call(
const ::boost::type_erasure::binding<Concept>& table,
const Op&
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
{
return ::boost::type_erasure::detail::call_impl<
typename ::boost::type_erasure::detail::get_signature<Op>::type,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u)),
Concept
>::template apply<
typename ::boost::type_erasure::detail::adapt_to_vtable<Op>::type
>(&table BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg));
}
template<
class Concept,
class Op
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
>
typename ::boost::type_erasure::detail::call_result<
Op,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u)),
Concept
>::type
call(
const ::boost::type_erasure::binding<Concept>& table,
const Op& f
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
{
::boost::type_erasure::require_match(table, f BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg));
return ::boost::type_erasure::unchecked_call(table, f BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg));
}
#if N != 0
template<
class Op
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
>
typename ::boost::type_erasure::detail::call_result<
Op,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u))
>::type
unchecked_call(
const Op&
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
{
return ::boost::type_erasure::detail::call_impl<
typename ::boost::type_erasure::detail::get_signature<Op>::type,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u))
>::template apply<
typename ::boost::type_erasure::detail::adapt_to_vtable<Op>::type
>(
::boost::type_erasure::detail::BOOST_PP_CAT(extract_table, N)(
(typename ::boost::type_erasure::detail::get_signature<Op>::type*)0,
BOOST_PP_ENUM_PARAMS(N, arg))
BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg)
);
}
template<
class Op
BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
>
typename ::boost::type_erasure::detail::call_result<
Op,
void(BOOST_PP_ENUM_BINARY_PARAMS(N, U, RREF u))
>::type
call(
const Op& f
BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
{
::boost::type_erasure::require_match(f BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg));
return ::boost::type_erasure::unchecked_call(f BOOST_TYPE_ERASURE_FORWARD_ARGS(N, U, arg));
}
#endif
#undef RREF
#undef BOOST_TYPE_ERASURE_FORWARD_ARGS
#undef BOOST_TYPE_ERASURE_FORWARD_ARGS_I
#undef BOOST_TYPE_ERASURE_GET_TABLE
#undef BOOST_TYPE_ERASURE_CONVERT_ARG
#undef N
#endif