boost/type_erasure/tuple.hpp
// Boost.TypeErasure library
//
// Copyright 2011-2012 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_TUPLE_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_TUPLE_HPP_INCLUDED
#include <boost/config.hpp>
#ifdef BOOST_TYPE_ERASURE_DOXYGEN
namespace boost {
namespace type_erasure {
/**
* @ref tuple is a Boost.Fusion Random Access Sequence containing
* @ref any "anys". @c Concept specifies the \Concept for each
* of the elements. The remaining arguments must be (possibly const
* and/or reference qualified) placeholders, which are the
* @ref placeholder "placeholders" of the elements.
*/
template<class Concept, class... T>
class tuple
{
public:
/**
* Constructs a tuple. Each element of @c args will
* be used to initialize the corresponding @ref any member.
* The @ref binding for the tuple elements is determined
* by mapping the placeholders in @c T to the corresponding
* types in @c U.
*/
template<class... U>
explicit tuple(U&&... args);
};
/**
* Returns the Nth @ref any in the tuple.
*/
template<int N, class Concept, class... T>
any<Concept, TN>& get(tuple<Concept, T...>& arg);
/** \overload */
template<int N, class Concept, class... T>
const any<Concept, TN>& get(const tuple<Concept, T...>& arg);
}
}
#elif !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
#include <boost/mpl/int.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/map.hpp>
#include <boost/mpl/insert.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/remove_const.hpp>
#include <boost/fusion/include/category_of.hpp>
#include <boost/fusion/include/iterator_facade.hpp>
#include <boost/fusion/include/sequence_facade.hpp>
#include <boost/type_erasure/any.hpp>
#include <boost/type_erasure/static_binding.hpp>
#include <boost/type_erasure/config.hpp>
namespace boost {
namespace type_erasure {
template<class Concept, class... T>
struct cons;
template<class Concept>
struct cons<Concept>
{
template<class Binding>
cons(const Binding&) {}
};
template<class Concept, class T0, class... T>
struct cons<Concept, T0, T...>
{
typedef any<Concept, T0> value_type;
typedef cons<Concept, T...> rest_type;
template<class Binding, class U0, class... U>
cons(const Binding& b, U0&& u0, U&&... u)
: value(std::forward<U0>(u0), b),
rest(b, std::forward<U>(u)...)
{}
any<Concept, T0> value;
cons<Concept, T...> rest;
};
namespace detail {
template<int N, class Cons>
struct cons_advance
{
typedef typename cons_advance<N-1, Cons>::type::rest_type type;
static const type& call(const Cons& c)
{
return cons_advance<N-1, Cons>::call(c).rest;
}
};
template<class Cons>
struct cons_advance<0, Cons>
{
typedef Cons type;
static const type& call(const Cons& c)
{
return c;
}
};
template<class... T>
struct make_map;
template<class T0, class... T>
struct make_map<T0, T...>
{
typedef typename ::boost::mpl::insert<
typename ::boost::type_erasure::detail::make_map<T...>::type,
T0
>::type type;
};
template<>
struct make_map<>
{
typedef ::boost::mpl::map0<> type;
};
}
/** INTERNAL ONLY */
template<class Tuple, int N>
class tuple_iterator :
public ::boost::fusion::iterator_facade<
tuple_iterator<Tuple, N>,
::boost::fusion::random_access_traversal_tag
>
{
public:
typedef ::boost::mpl::int_<N> index;
explicit tuple_iterator(Tuple& t_arg) : t(&t_arg) {}
template<class It>
struct value_of
{
typedef typename Tuple::template value_at<Tuple, mpl::int_<N> >::type type;
};
template<class It>
struct deref
{
typedef typename Tuple::template at<Tuple, mpl::int_<N> >::type type;
static type call(It it)
{
return Tuple::template at<Tuple, mpl::int_<N> >::call(*it.t);
}
};
template<class It, class M>
struct advance
{
typedef tuple_iterator<Tuple, (It::index::value+M::value)> type;
static type call(It it) { return type(*it.t); }
};
template<class It>
struct next : advance<It, ::boost::mpl::int_<1> > {};
template<class It>
struct prior : advance<It, ::boost::mpl::int_<-1> > {};
template<class It1, class It2>
struct distance
{
typedef typename ::boost::mpl::minus<
typename It2::index,
typename It1::index
>::type type;
static type call(It1, It2) { return type(); }
};
private:
Tuple* t;
};
template<class Concept, class... T>
class tuple :
public ::boost::fusion::sequence_facade<
::boost::type_erasure::tuple<Concept, T...>,
::boost::fusion::forward_traversal_tag
>
{
public:
template<class... U>
explicit tuple(U&&... args)
: impl(
::boost::type_erasure::make_binding<
typename ::boost::type_erasure::detail::make_map<
::boost::mpl::pair<
typename ::boost::remove_const<
typename ::boost::remove_reference<T>::type
>::type,
typename ::boost::remove_const<
typename ::boost::remove_reference<U>::type
>::type
>...
>::type
>(),
std::forward<U>(args)...)
{}
template<class Seq>
struct begin
{
typedef ::boost::type_erasure::tuple_iterator<
Seq,
0
> type;
static type call(Seq& seq) { return type(seq); }
};
template<class Seq>
struct end
{
typedef ::boost::type_erasure::tuple_iterator<
Seq,
sizeof...(T)
> type;
static type call(Seq& seq) { return type(seq); }
};
template<class Seq>
struct size
{
typedef ::boost::mpl::int_<sizeof...(T)> type;
static type call(Seq& seq) { return type(); }
};
template<class Seq>
struct empty
{
typedef ::boost::mpl::bool_<sizeof...(T) == 0> type;
static type call(Seq& seq) { return type(); }
};
template<class Seq, class N>
struct at
{
typedef typename ::boost::type_erasure::detail::cons_advance<
N::value,
::boost::type_erasure::cons<Concept, T...>
>::type::value_type value_type;
typedef typename ::boost::mpl::if_< ::boost::is_const<Seq>,
const value_type&,
value_type&
>::type type;
static type call(Seq& seq)
{
return const_cast<type>(
::boost::type_erasure::detail::cons_advance<
N::value,
::boost::type_erasure::cons<Concept, T...>
>::call(seq.impl).value
);
}
};
template<class Seq, class N>
struct value_at
{
typedef typename ::boost::type_erasure::detail::cons_advance<
N::value,
::boost::type_erasure::cons<Concept, T...>
>::type::value_type value_type;
};
::boost::type_erasure::cons<Concept, T...> impl;
};
template<int N, class Concept, class... T>
typename ::boost::type_erasure::detail::cons_advance<
N,
::boost::type_erasure::cons<Concept, T...>
>::type::value_type& get(::boost::type_erasure::tuple<Concept, T...>& t)
{
return const_cast<
typename ::boost::type_erasure::detail::cons_advance<
N,
::boost::type_erasure::cons<Concept, T...>
>::type::value_type&
>(
::boost::type_erasure::detail::cons_advance<N,
::boost::type_erasure::cons<Concept, T...>
>::call(t.impl).value
);
}
template<int N, class Concept, class... T>
const typename ::boost::type_erasure::detail::cons_advance<
N,
::boost::type_erasure::cons<Concept, T...>
>::type::value_type& get(const ::boost::type_erasure::tuple<Concept, T...>& t)
{
return ::boost::type_erasure::detail::cons_advance<
N,
::boost::type_erasure::cons<Concept, T...>
>::call(t.impl).value;
}
}
}
#else
#include <boost/mpl/int.hpp>
#include <boost/mpl/minus.hpp>
#include <boost/mpl/equal_to.hpp>
#include <boost/mpl/map.hpp>
#include <boost/fusion/include/category_of.hpp>
#include <boost/fusion/include/iterator_facade.hpp>
#include <boost/fusion/include/sequence_facade.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/repetition/repeat.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/enum_trailing_params.hpp>
#include <boost/preprocessor/repetition/enum_binary_params.hpp>
#include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
#include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
#include <boost/type_erasure/any.hpp>
#include <boost/type_erasure/static_binding.hpp>
#include <boost/type_erasure/config.hpp>
namespace boost {
namespace type_erasure {
/** INTERNAL ONLY */
struct na {};
namespace detail {
template<int N, class Tuple>
struct get_impl;
template<class Concept,
BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(
BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, class T, ::boost::type_erasure::na)>
struct tuple_storage;
}
/** INTERNAL ONLY */
template<class Tuple, int N>
class tuple_iterator :
public ::boost::fusion::iterator_facade<
tuple_iterator<Tuple, N>,
::boost::fusion::random_access_traversal_tag
>
{
public:
typedef ::boost::mpl::int_<N> index;
explicit tuple_iterator(Tuple& t_arg) : t(&t_arg) {}
template<class It>
struct value_of
{
typedef typename ::boost::type_erasure::detail::get_impl<
It::index::value,
Tuple
>::value_type type;
};
template<class It>
struct deref :
::boost::type_erasure::detail::get_impl<It::index::value, Tuple>
{
typedef typename ::boost::type_erasure::detail::get_impl<
It::index::value,
Tuple
>::type type;
static type call(It it)
{
return ::boost::type_erasure::detail::get_impl<
It::index::value,
Tuple
>::call(*it.t);
}
};
template<class It, class M>
struct advance
{
typedef tuple_iterator<Tuple, (It::index::value+M::value)> type;
static type call(It it) { return type(*it.t); }
};
template<class It>
struct next : advance<It, ::boost::mpl::int_<1> > {};
template<class It>
struct prior : advance<It, ::boost::mpl::int_<-1> > {};
template<class It1, class It2>
struct distance
{
typedef typename ::boost::mpl::minus<
typename It2::index,
typename It1::index
>::type type;
static type call(It1, It2) { return type(); }
};
private:
Tuple* t;
};
/** INTERNAL ONLY */
template<class Derived>
struct tuple_base :
::boost::fusion::sequence_facade<
Derived,
::boost::fusion::random_access_traversal_tag
>
{
template<class Seq>
struct begin
{
typedef ::boost::type_erasure::tuple_iterator<Seq, 0> type;
static type call(Seq& seq) { return type(seq); }
};
template<class Seq>
struct end
{
typedef ::boost::type_erasure::tuple_iterator<
Seq,
Seq::tuple_size::value
> type;
static type call(Seq& seq) { return type(seq); }
};
template<class Seq>
struct size
{
typedef typename Seq::tuple_size type;
static type call(Seq& seq) { return type(); }
};
template<class Seq>
struct empty
{
typedef typename boost::mpl::equal_to<
typename Seq::tuple_size,
boost::mpl::int_<0>
>::type type;
static type call(Seq& seq) { return type(); }
};
template<class Seq, class N>
struct at : ::boost::type_erasure::detail::get_impl<N::value, Seq> {};
template<class Seq, class N>
struct value_at
{
typedef typename ::boost::type_erasure::detail::get_impl<
N::value,
Seq
>::value_type type;
};
};
template<class Concept,
BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(
BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, class T, ::boost::type_erasure::na)>
class tuple;
template<
int N,
class Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, class T)
>
typename detail::get_impl<
N,
tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>
>::type get(
tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>& arg)
{
return detail::get_impl<
N,
tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>
>::call(arg);
}
template<
int N,
class Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, class T)
>
typename detail::get_impl<
N,
const tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>
>::type get(
const tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>& arg)
{
return detail::get_impl<
N,
const tuple<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, T)
>
>::call(arg);
}
/** INTERNAL ONLY */
#define BOOST_PP_FILENAME_1 <boost/type_erasure/tuple.hpp>
/** INTERNAL ONLY */
#define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE)
#include BOOST_PP_ITERATE()
}
}
#endif
#endif
#else
#define N BOOST_PP_ITERATION()
#define BOOST_TYPE_ERASURE_TAG_TYPEDEF(z, n, data) \
typedef BOOST_PP_CAT(T, n) BOOST_PP_CAT(tag_type, n); \
typedef typename ::boost::remove_reference<BOOST_PP_CAT(T, n)>::type \
BOOST_PP_CAT(tag, n);
#define BOOST_TYPE_ERASURE_PAIR(z, n, data) \
::boost::mpl::pair<BOOST_PP_CAT(tag, n), BOOST_PP_CAT(U, n)>
#define BOOST_TYPE_ERASURE_CONSTRUCT(z, n, data)\
BOOST_PP_CAT(t, n)(BOOST_PP_CAT(u, n), table)
#define BOOST_TYPE_ERASURE_TUPLE_MEMBER(z, n, data)\
::boost::type_erasure::any<Concept, BOOST_PP_CAT(T, n)> BOOST_PP_CAT(t, n);
#if N == 1
#define BOOST_TYPE_ERASURE_EXPLICIT explicit
#else
#define BOOST_TYPE_ERASURE_EXPLICIT
#endif
namespace detail {
template<class Concept BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
struct tuple_storage
#if N != BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE
<Concept BOOST_PP_ENUM_TRAILING_PARAMS(N, T)>
#endif
{
#if N
template<class Table BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
tuple_storage(
const Table& table BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, &u))
:
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_CONSTRUCT, ~) {}
#else
template<class Table>
explicit tuple_storage(const Table&) {}
#endif
BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_TUPLE_MEMBER, `)
};
#if N != BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE
template<class Tuple>
struct get_impl<N, Tuple>
{
typedef any<
typename Tuple::concept_type,
typename Tuple::BOOST_PP_CAT(tag_type, N)
> value_type;
typedef value_type& type;
static type call(Tuple& arg)
{ return arg.impl.BOOST_PP_CAT(t, N); }
};
template<class Tuple>
struct get_impl<N, const Tuple>
{
typedef any<
typename Tuple::concept_type,
typename Tuple::BOOST_PP_CAT(tag_type, N)
> value_type;
typedef const value_type& type;
static type call(const Tuple& arg)
{ return arg.impl.BOOST_PP_CAT(t, N); }
};
#endif
}
template<class Concept BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)>
class tuple
#if N != BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE
<Concept BOOST_PP_ENUM_TRAILING_PARAMS(N, T)>
#endif
: public tuple_base<tuple<Concept BOOST_PP_ENUM_TRAILING_PARAMS(N, T)> >
{
typedef Concept concept_type;
BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_TAG_TYPEDEF, ~)
public:
typedef ::boost::mpl::int_<N> tuple_size;
#if N
template<BOOST_PP_ENUM_PARAMS(N, class U)>
#endif
BOOST_TYPE_ERASURE_EXPLICIT
tuple(BOOST_PP_ENUM_BINARY_PARAMS(N, U, &u)) :
impl(
::boost::type_erasure::make_binding<
::boost::mpl::map<
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_PAIR, ~)
>
>()
BOOST_PP_ENUM_TRAILING_PARAMS(N, u)
)
{}
#if N
template<BOOST_PP_ENUM_PARAMS(N, class U)>
BOOST_TYPE_ERASURE_EXPLICIT
tuple(BOOST_PP_ENUM_BINARY_PARAMS(N, const U, &u)) :
impl(
::boost::type_erasure::make_binding<
::boost::mpl::map<
BOOST_PP_ENUM(N, BOOST_TYPE_ERASURE_PAIR, ~)
>
>()
BOOST_PP_ENUM_TRAILING_PARAMS(N, u)
)
{}
#endif
private:
template<int M, class Tuple>
friend struct ::boost::type_erasure::detail::get_impl;
::boost::type_erasure::detail::tuple_storage<
Concept
BOOST_PP_ENUM_TRAILING_PARAMS(N, T)
> impl;
};
#undef BOOST_TYPE_ERASURE_EXPLICIT
#undef BOOST_TYPE_ERASURE_TUPLE_MEMBER
#undef BOOST_TYPE_ERASURE_CONSTRUCT
#undef BOOST_TYPE_ERASURE_PAIR
#undef BOOST_TYPE_ERASURE_TAG_TYPEDEF
#undef N
#endif