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///////////////////////////////////////////////////////////////////////////////
/// \file deep_copy.hpp
/// Replace all nodes stored by reference by nodes stored by value.
//
// 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_DEEP_COPY_HPP_EAN_11_21_2006
#define BOOST_PROTO_DEEP_COPY_HPP_EAN_11_21_2006
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/mpl/if.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/proto/proto_fwd.hpp>
#include <boost/proto/args.hpp>
#include <boost/proto/expr.hpp>
namespace boost { namespace proto
{
namespace detail
{
template<typename Expr, long Arity = Expr::proto_arity_c>
struct deep_copy_impl;
template<typename Expr>
struct deep_copy_impl<Expr, 0>
{
typedef
typename base_expr<
typename Expr::proto_domain
, tag::terminal
, term<typename term_traits<typename Expr::proto_child0>::value_type>
>::type
expr_type;
typedef typename Expr::proto_generator proto_generator;
typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type;
template<typename Expr2, typename S, typename D>
result_type operator()(Expr2 const &e, S const &, D const &) const
{
return proto_generator()(expr_type::make(e.proto_base().child0));
}
};
}
namespace result_of
{
/// \brief A metafunction for calculating the return type
/// of \c proto::deep_copy().
///
/// A metafunction for calculating the return type
/// of \c proto::deep_copy(). The type parameter \c Expr
/// should be the type of a Proto expression tree.
/// It should not be a reference type, nor should it
/// be cv-qualified.
template<typename Expr>
struct deep_copy
{
typedef
typename detail::deep_copy_impl<
BOOST_PROTO_UNCVREF(Expr)
>::result_type
type;
};
}
namespace functional
{
/// \brief A PolymorphicFunctionObject type for deep-copying
/// Proto expression trees.
///
/// A PolymorphicFunctionObject type for deep-copying
/// Proto expression trees. When a tree is deep-copied,
/// all internal nodes and most terminals held by reference
/// are instead held by value.
///
/// \attention Terminals of reference-to-function type are
/// left unchanged. Terminals of reference-to-array type are
/// stored by value, which can cause a large amount of data
/// to be passed by value and stored on the stack.
struct deep_copy
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result;
template<typename This, typename Expr>
struct result<This(Expr)>
{
typedef
typename detail::deep_copy_impl<
BOOST_PROTO_UNCVREF(Expr)
>::result_type
type;
};
/// \brief Deep-copies a Proto expression tree, turning all
/// nodes and terminals held by reference into ones held by
/// value.
template<typename Expr>
typename result_of::deep_copy<Expr>::type
operator()(Expr const &e) const
{
return proto::detail::deep_copy_impl<Expr>()(e, 0, 0);
}
};
}
/// \brief A function for deep-copying
/// Proto expression trees.
///
/// A function for deep-copying
/// Proto expression trees. When a tree is deep-copied,
/// all internal nodes and most terminals held by reference
/// are instead held by value.
///
/// \attention Terminals of reference-to-function type are
/// left unchanged.
///
/// \sa proto::functional::deep_copy.
template<typename Expr>
typename proto::result_of::deep_copy<Expr>::type
deep_copy(Expr const &e)
{
return proto::detail::deep_copy_impl<Expr>()(e, 0, 0);
}
/// \brief A PrimitiveTransform for deep-copying
/// Proto expression trees.
///
/// A PrimitiveTransform for deep-copying
/// Proto expression trees. When a tree is deep-copied,
/// all internal nodes and most terminals held by reference
/// are instead held by value.
///
/// \attention Terminals of reference-to-function type are
/// left unchanged.
///
/// \sa proto::functional::deep_copy.
struct _deep_copy
: proto::transform<_deep_copy>
{
template<typename E, typename S, typename D>
struct impl
: detail::deep_copy_impl<BOOST_PROTO_UNCVREF(E)>
{};
};
namespace detail
{
// include the definition of deep_copy_impl
#include <boost/proto/detail/deep_copy.hpp>
}
}}
#endif // BOOST_PROTO_COMPILER_DEEP_COPY_HPP_EAN_11_21_2006