boost/proto/context/default.hpp
#ifndef BOOST_PP_IS_ITERATING
///////////////////////////////////////////////////////////////////////////////
/// \file default.hpp
/// Definintion of default_context, a default evaluation context for
/// proto::eval() that uses Boost.Typeof to deduce return types
/// of the built-in operators.
//
// Copyright 2008 Eric Niebler. 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 BOOST_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007
#define BOOST_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007
#include <boost/proto/detail/prefix.hpp> // must be first include
#include <boost/config.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/repetition/enum_shifted.hpp>
#include <boost/utility/result_of.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/is_function.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/is_member_pointer.hpp>
#include <boost/type_traits/is_member_object_pointer.hpp>
#include <boost/type_traits/is_member_function_pointer.hpp>
#include <boost/proto/proto_fwd.hpp>
#include <boost/proto/tags.hpp>
#include <boost/proto/eval.hpp>
#include <boost/proto/traits.hpp> // for proto::child_c()
#include <boost/proto/detail/decltype.hpp>
#include <boost/proto/detail/suffix.hpp> // must be last include
namespace boost { namespace proto
{
/// INTERNAL ONLY
///
#define UNREF(x) typename boost::remove_reference<x>::type
namespace context
{
template<
typename Expr
, typename Context
, typename Tag BOOST_PROTO_WHEN_BUILDING_DOCS(= typename Expr::proto_tag)
, long Arity BOOST_PROTO_WHEN_BUILDING_DOCS(= Expr::proto_arity::value)
>
struct default_eval
{};
/// INTERNAL ONLY
///
#define BOOST_PROTO_UNARY_OP_RESULT(OP, TAG, MAKE) \
template<typename Expr, typename Context> \
struct default_eval<Expr, Context, TAG, 1> \
{ \
private: \
typedef typename proto::result_of::child_c<Expr, 0>::type e0; \
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; \
public: \
BOOST_PROTO_DECLTYPE_(OP proto::detail::MAKE<r0>(), result_type) \
result_type operator ()(Expr &expr, Context &ctx) const \
{ \
return OP proto::eval(proto::child_c<0>(expr), ctx); \
} \
}; \
/**/
/// INTERNAL ONLY
///
#define BOOST_PROTO_BINARY_OP_RESULT(OP, TAG, LMAKE, RMAKE) \
template<typename Expr, typename Context> \
struct default_eval<Expr, Context, TAG, 2> \
{ \
private: \
typedef typename proto::result_of::child_c<Expr, 0>::type e0; \
typedef typename proto::result_of::child_c<Expr, 1>::type e1; \
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; \
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; \
public: \
BOOST_PROTO_DECLTYPE_( \
proto::detail::LMAKE<r0>() OP proto::detail::RMAKE<r1>() \
, result_type \
) \
result_type operator ()(Expr &expr, Context &ctx) const \
{ \
return proto::eval( \
proto::child_c<0>(expr), ctx) OP proto::eval(proto::child_c<1>(expr) \
, ctx \
); \
} \
}; \
/**/
BOOST_PROTO_UNARY_OP_RESULT(+, proto::tag::unary_plus, make)
BOOST_PROTO_UNARY_OP_RESULT(-, proto::tag::negate, make)
BOOST_PROTO_UNARY_OP_RESULT(*, proto::tag::dereference, make)
BOOST_PROTO_UNARY_OP_RESULT(~, proto::tag::complement, make)
BOOST_PROTO_UNARY_OP_RESULT(&, proto::tag::address_of, make)
BOOST_PROTO_UNARY_OP_RESULT(!, proto::tag::logical_not, make)
BOOST_PROTO_UNARY_OP_RESULT(++, proto::tag::pre_inc, make_mutable)
BOOST_PROTO_UNARY_OP_RESULT(--, proto::tag::pre_dec, make_mutable)
BOOST_PROTO_BINARY_OP_RESULT(<<, proto::tag::shift_left, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(>>, proto::tag::shift_right, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(*, proto::tag::multiplies, make, make)
BOOST_PROTO_BINARY_OP_RESULT(/, proto::tag::divides, make, make)
BOOST_PROTO_BINARY_OP_RESULT(%, proto::tag::modulus, make, make)
BOOST_PROTO_BINARY_OP_RESULT(+, proto::tag::plus, make, make)
BOOST_PROTO_BINARY_OP_RESULT(-, proto::tag::minus, make, make)
BOOST_PROTO_BINARY_OP_RESULT(<, proto::tag::less, make, make)
BOOST_PROTO_BINARY_OP_RESULT(>, proto::tag::greater, make, make)
BOOST_PROTO_BINARY_OP_RESULT(<=, proto::tag::less_equal, make, make)
BOOST_PROTO_BINARY_OP_RESULT(>=, proto::tag::greater_equal, make, make)
BOOST_PROTO_BINARY_OP_RESULT(==, proto::tag::equal_to, make, make)
BOOST_PROTO_BINARY_OP_RESULT(!=, proto::tag::not_equal_to, make, make)
BOOST_PROTO_BINARY_OP_RESULT(||, proto::tag::logical_or, make, make)
BOOST_PROTO_BINARY_OP_RESULT(&&, proto::tag::logical_and, make, make)
BOOST_PROTO_BINARY_OP_RESULT(&, proto::tag::bitwise_and, make, make)
BOOST_PROTO_BINARY_OP_RESULT(|, proto::tag::bitwise_or, make, make)
BOOST_PROTO_BINARY_OP_RESULT(^, proto::tag::bitwise_xor, make, make)
BOOST_PROTO_BINARY_OP_RESULT(=, proto::tag::assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(<<=, proto::tag::shift_left_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(>>=, proto::tag::shift_right_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(*=, proto::tag::multiplies_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(/=, proto::tag::divides_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(%=, proto::tag::modulus_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(+=, proto::tag::plus_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(-=, proto::tag::minus_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(&=, proto::tag::bitwise_and_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(|=, proto::tag::bitwise_or_assign, make_mutable, make)
BOOST_PROTO_BINARY_OP_RESULT(^=, proto::tag::bitwise_xor_assign, make_mutable, make)
#undef BOOST_PROTO_UNARY_OP_RESULT
#undef BOOST_PROTO_BINARY_OP_RESULT
/// INTERNAL ONLY
template<typename Expr, typename Context>
struct is_member_function_eval
{
typedef typename proto::result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
typedef typename remove_const<typename remove_reference<r1>::type>::type uncvref_r1;
typedef typename is_member_function_pointer<uncvref_r1>::type type;
BOOST_STATIC_CONSTANT(bool, value = type::value);
};
/// INTERNAL ONLY
template<typename Expr, typename Context, bool IsMemFunCall>
struct memfun_eval
{
private:
typedef typename result_of::child_c<Expr, 0>::type e0;
typedef typename result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
public:
typedef typename detail::mem_ptr_fun<r0, r1>::result_type result_type;
result_type operator ()(Expr &expr, Context &ctx) const
{
return detail::mem_ptr_fun<r0, r1>()(
proto::eval(proto::child_c<0>(expr), ctx)
, proto::eval(proto::child_c<1>(expr), ctx)
);
}
};
/// INTERNAL ONLY
template<typename Expr, typename Context>
struct memfun_eval<Expr, Context, true>
{
private:
typedef typename result_of::child_c<Expr, 0>::type e0;
typedef typename result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
public:
typedef detail::memfun<r0, r1> result_type;
result_type const operator ()(Expr &expr, Context &ctx) const
{
return detail::memfun<r0, r1>(
proto::eval(proto::child_c<0>(expr), ctx)
, proto::eval(proto::child_c<1>(expr), ctx)
);
}
};
template<typename Expr, typename Context>
struct default_eval<Expr, Context, tag::mem_ptr, 2>
: memfun_eval<Expr, Context, is_member_function_eval<Expr, Context>::value>
{};
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::terminal, 0>
{
typedef
typename proto::result_of::value<Expr &>::type
result_type;
result_type operator ()(Expr &expr, Context &) const
{
return proto::value(expr);
}
};
// Handle post-increment specially.
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::post_inc, 1>
{
private:
typedef typename proto::result_of::child_c<Expr, 0>::type e0;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
public:
BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() ++, result_type)
result_type operator ()(Expr &expr, Context &ctx) const
{
return proto::eval(proto::child_c<0>(expr), ctx) ++;
}
};
// Handle post-decrement specially.
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::post_dec, 1>
{
private:
typedef typename proto::result_of::child_c<Expr, 0>::type e0;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
public:
BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() --, result_type)
result_type operator ()(Expr &expr, Context &ctx) const
{
return proto::eval(proto::child_c<0>(expr), ctx) --;
}
};
// Handle subscript specially.
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::subscript, 2>
{
private:
typedef typename proto::result_of::child_c<Expr, 0>::type e0;
typedef typename proto::result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
public:
BOOST_PROTO_DECLTYPE_(proto::detail::make_subscriptable<r0>()[proto::detail::make<r1>()], result_type)
result_type operator ()(Expr &expr, Context &ctx) const
{
return proto::eval(proto::child_c<0>(expr), ctx)[proto::eval(proto::child_c<1>(expr), ctx)];
}
};
// Handle if_else_ specially.
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::if_else_, 3>
{
private:
typedef typename proto::result_of::child_c<Expr, 0>::type e0;
typedef typename proto::result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::child_c<Expr, 2>::type e2;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
typedef typename proto::result_of::eval<UNREF(e2), Context>::type r2;
public:
BOOST_PROTO_DECLTYPE_(
proto::detail::make<r0>()
? proto::detail::make<r1>()
: proto::detail::make<r2>()
, result_type
)
result_type operator ()(Expr &expr, Context &ctx) const
{
return proto::eval(proto::child_c<0>(expr), ctx)
? proto::eval(proto::child_c<1>(expr), ctx)
: proto::eval(proto::child_c<2>(expr), ctx);
}
};
// Handle comma specially.
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::comma, 2>
{
private:
typedef typename proto::result_of::child_c<Expr, 0>::type e0;
typedef typename proto::result_of::child_c<Expr, 1>::type e1;
typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
public:
typedef typename proto::detail::comma_result<r0, r1>::type result_type;
result_type operator ()(Expr &expr, Context &ctx) const
{
return proto::eval(proto::child_c<0>(expr), ctx), proto::eval(proto::child_c<1>(expr), ctx);
}
};
// Handle function specially
#define EVAL_TYPE(Z, N, DATA) \
typename proto::result_of::eval< \
typename remove_reference< \
typename proto::result_of::child_c<DATA, N>::type \
>::type \
, Context \
>::type \
/**/
#define EVAL(Z, N, DATA) \
proto::eval(proto::child_c<N>(DATA), context) \
/**/
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::function, 1>
{
typedef
typename proto::detail::result_of_fixup<EVAL_TYPE(~, 0, Expr)>::type
function_type;
typedef
typename boost::result_of<function_type()>::type
result_type;
result_type operator ()(Expr &expr, Context &context) const
{
return EVAL(~, 0, expr)();
}
};
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::function, 2>
{
typedef
typename proto::detail::result_of_fixup<EVAL_TYPE(~, 0, Expr)>::type
function_type;
typedef
typename detail::result_of_<function_type(EVAL_TYPE(~, 1, Expr))>::type
result_type;
result_type operator ()(Expr &expr, Context &context) const
{
return this->invoke(
expr
, context
, is_member_function_pointer<function_type>()
, is_member_object_pointer<function_type>()
);
}
private:
result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::false_) const
{
return EVAL(~, 0, expr)(EVAL(~, 1, expr));
}
result_type invoke(Expr &expr, Context &context, mpl::true_, mpl::false_) const
{
using namespace detail::get_pointer_;
return (get_pointer(EVAL(~, 1, expr)) ->* EVAL(~, 0, expr))();
}
result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::true_) const
{
using namespace detail::get_pointer_;
return (get_pointer(EVAL(~, 1, expr)) ->* EVAL(~, 0, expr));
}
};
#define BOOST_PP_ITERATION_PARAMS_1 (3, (3, BOOST_PROTO_MAX_ARITY, <boost/proto/context/default.hpp>))
#include BOOST_PP_ITERATE()
#undef EVAL_TYPE
#undef EVAL
/// default_context
///
struct default_context
{
/// default_context::eval
///
template<typename Expr, typename ThisContext = default_context const>
struct eval
: default_eval<Expr, ThisContext>
{};
};
} // namespace context
}} // namespace boost::proto
#undef UNREF
#endif
#else
#define N BOOST_PP_ITERATION()
template<typename Expr, typename Context>
struct default_eval<Expr, Context, proto::tag::function, N>
{
typedef
typename proto::detail::result_of_fixup<EVAL_TYPE(~, 0, Expr)>::type
function_type;
typedef
typename boost::result_of<
function_type(BOOST_PP_ENUM_SHIFTED(N, EVAL_TYPE, Expr))
>::type
result_type;
result_type operator ()(Expr &expr, Context &context) const
{
return this->invoke(expr, context, is_member_function_pointer<function_type>());
}
private:
result_type invoke(Expr &expr, Context &context, mpl::false_) const
{
return EVAL(~, 0, expr)(BOOST_PP_ENUM_SHIFTED(N, EVAL, expr));
}
result_type invoke(Expr &expr, Context &context, mpl::true_) const
{
#define M0(Z, M, expr) BOOST_PP_COMMA_IF(BOOST_PP_SUB(M, 2)) EVAL(Z, M, expr)
using namespace detail::get_pointer_;
return (get_pointer(EVAL(~, 1, expr)) ->* EVAL(~, 0, expr))(
BOOST_PP_REPEAT_FROM_TO(2, N, M0, expr)
);
#undef M0
}
};
#undef N
#endif
