boost/phoenix/scope/detail/local_variable.hpp
/*=============================================================================
Copyright (c) 2001-2007 Joel de Guzman
Copyright (c) 2004 Daniel Wallin
Copyright (c) 2011 Thomas Heller
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)
==============================================================================*/
#ifndef PHOENIX_SCOPE_DETAIL_LOCAL_VARIABLE_HPP
#define PHOENIX_SCOPE_DETAIL_LOCAL_VARIABLE_HPP
#include <boost/mpl/int.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/fusion/include/at.hpp>
#include <boost/fusion/include/value_at.hpp>
#include <boost/preprocessor/enum.hpp>
#include <boost/preprocessor/repeat.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/is_reference.hpp>
#define BOOST_PHOENIX_MAP_LOCAL_TEMPLATE_PARAM(z, n, data) \
typename T##n = unused<n>
#define BOOST_PHOENIX_MAP_LOCAL_DISPATCH(z, n, data) \
typedef char(&result##n)[n+2]; \
static result##n get(T##n*);
namespace boost { namespace phoenix
{
template <typename Env, typename OuterEnv, typename Locals, typename Map>
struct scoped_environment;
namespace detail
{
template <typename Key>
struct local
{
typedef Key key_type;
};
namespace result_of
{
template <typename Locals, typename Context>
struct initialize_locals;
template <typename Context>
struct initialize_locals<vector0<>, Context>
{
typedef vector0<> type;
};
#define M1(Z, N, D) \
typename boost::phoenix::result_of::eval< \
BOOST_PP_CAT(A, N) \
, Context \
>::type \
/**/
#define M0(Z, N, D) \
template <BOOST_PHOENIX_typename_A(N), typename Context> \
struct initialize_locals< \
BOOST_PP_CAT(vector, N)< \
BOOST_PHOENIX_A(N) \
> \
, Context \
> \
{ \
typedef \
BOOST_PP_CAT(vector, N)< \
BOOST_PP_ENUM(N, M1, _) \
> \
type; \
}; \
/**/
BOOST_PP_REPEAT_FROM_TO(1, BOOST_PHOENIX_LIMIT, M0, _)
#undef M0
}
template <typename Context>
vector0<>
initialize_locals(vector0<> const &, Context const &)
{
vector0<> vars;
return vars;
}
#define M2(Z, N, D) \
eval(locals. BOOST_PP_CAT(a, N), ctx) \
/**/
#define M0(Z, N, D) \
template <BOOST_PHOENIX_typename_A(N), typename Context> \
BOOST_PP_CAT(vector, N)<BOOST_PP_ENUM(N, M1, _)> \
initialize_locals( \
BOOST_PP_CAT(vector, N)<BOOST_PHOENIX_A(N)> const & locals \
, Context const & ctx \
) \
{ \
BOOST_PP_CAT(vector, N)<BOOST_PP_ENUM(N, M1, _)> vars \
= {BOOST_PP_ENUM(N, M2, _)}; \
return vars; \
} \
/**/
BOOST_PP_REPEAT_FROM_TO(1, BOOST_PHOENIX_LIMIT, M0, _)
#undef M0
#undef M1
#undef M2
template <int N>
struct unused;
template <
BOOST_PP_ENUM(
BOOST_PHOENIX_LOCAL_LIMIT
, BOOST_PHOENIX_MAP_LOCAL_TEMPLATE_PARAM
, _
)
>
struct map_local_index_to_tuple
{
typedef char(¬_found)[1];
static not_found get(...);
BOOST_PP_REPEAT(BOOST_PHOENIX_LOCAL_LIMIT, BOOST_PHOENIX_MAP_LOCAL_DISPATCH, _)
};
template<typename T>
T* generate_pointer();
template <typename Map, typename Tag>
struct get_index
{
BOOST_STATIC_CONSTANT(int,
value = (
static_cast<int>((sizeof(Map::get(generate_pointer<Tag>()))) / sizeof(char)) - 2
));
// if value == -1, Tag is not found
typedef mpl::int_<value> type;
};
template <typename Local, typename Env>
struct apply_local;
template <typename Local, typename Env>
struct outer_local
{
typedef typename
apply_local<Local, typename Env::outer_env_type>::type
type;
};
template <typename Locals, int Index>
struct get_local_or_void
{
typedef typename
mpl::eval_if_c<
Index < Locals::size_value
, fusion::result_of::at_c<Locals, Index>
, mpl::identity<fusion::void_>
>::type
type;
};
template <typename Local, typename Env, int Index>
struct get_local_from_index
{
typedef typename
mpl::eval_if_c<
Index == -1
, outer_local<Local, Env>
, get_local_or_void<typename Env::locals_type, Index>
>::type
type;
};
template <typename Local, typename Env>
struct get_local
{
static const int index_value = get_index<typename Env::map_type, Local>::value;
typedef typename
get_local_from_index<Local, Env, index_value>::type
type;
};
template <typename Local, typename Env>
struct apply_local
{
// $$$ TODO: static assert that Env is a scoped_environment $$$
typedef typename get_local<Local, Env>::type type;
};
template <typename Key>
struct eval_local
{
template <typename RT, int Index, typename Env>
static RT
get(Env const& env, mpl::false_)
{
return RT(fusion::at_c<Index>(env.locals));
}
template <typename RT, int Index, typename Env>
static RT
get(Env const& env, mpl::true_)
{
static const int index_value = get_index<typename Env::outer_env_type::map_type, detail::local<Key> >::value;
return get<RT, index_value>(
env.outer_env
, mpl::bool_<index_value == -1>());
}
template <typename RT, int Index, typename Env>
static RT
get(Env const& env)
{
return get<RT, Index>(
env
, mpl::bool_<Index == -1>());
}
};
}
}}
#undef BOOST_PHOENIX_MAP_LOCAL_TEMPLATE_PARAM
#undef BOOST_PHOENIX_MAP_LOCAL_DISPATCH
#endif
