Update of /cvsroot/boost/boost/boost/xpressive/proto/context
In directory sc8-pr-cvs3.sourceforge.net:/tmp/cvs-serv10193/context
Modified Files:
callable.hpp default.hpp null.hpp
Log Message:
callable_context's fallback is configurable
Index: callable.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/xpressive/proto/context/callable.hpp,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -d -r1.2 -r1.3
--- callable.hpp 26 Jun 2007 00:16:04 -0000 1.2
+++ callable.hpp 1 Jul 2007 07:43:05 -0000 1.3
@@ -24,21 +24,36 @@
#include <boost/preprocessor/repetition/enum_trailing.hpp>
#include <boost/preprocessor/arithmetic/inc.hpp>
#include <boost/preprocessor/selection/max.hpp>
+ #include <boost/mpl/if.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/utility/result_of.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/xpressive/proto/proto_fwd.hpp>
- #include <boost/xpressive/proto/tags.hpp>
- #include <boost/xpressive/proto/eval.hpp>
- #include <boost/xpressive/proto/context/default.hpp>
#include <boost/xpressive/proto/detail/suffix.hpp> // must be last include
namespace boost { namespace proto
{
+ namespace detail
+ {
+ struct private_type_
+ {
+ private_type_ const &operator,(int) const;
+ };
+
+ template<typename T>
+ yes_type check_is_expr_handled(T const &);
+
+ no_type check_is_expr_handled(private_type_ const &);
+
+ template<typename Context, long Arity>
+ struct callable_context_wrapper;
+
+ template<typename Expr, typename Context, long Arity =
Expr::proto_arity::value>
+ struct is_expr_handled;
+ }
template<typename Expr, typename Context, long Arity =
Expr::proto_arity::value>
- struct callable_eval
- {};
+ struct callable_eval;
#define BOOST_PROTO_ARG_N_TYPE(Z, N, Expr)
\
typename proto::result_of::arg_c<Expr, N>::const_reference
\
@@ -59,14 +74,18 @@
/// callable_context
///
- template<typename Context>
+ template<typename Context, typename DefaultCtx>
struct callable_context
{
/// callable_context::eval
///
- template<typename Expr>
+ template<typename Expr, typename ThisContext = Context>
struct eval
- : callable_eval<Expr, Context>
+ : mpl::if_<
+ detail::is_expr_handled<Expr, Context>
+ , callable_eval<Expr, ThisContext>
+ , typename DefaultCtx::template eval<Expr, Context>
+ >::type
{};
};
@@ -79,25 +98,44 @@
#define N BOOST_PP_ITERATION()
#define ARG_COUNT BOOST_PP_MAX(1, N)
- template<typename Expr, typename Context>
- struct callable_eval<Expr, Context, N>
+ namespace detail
{
- private:
- /// INTERNAL ONLY
- ///
- typedef typename remove_cv<Context>::type context_type;
- /// INTERNAL ONLY
- ///
- struct inner_context
- : context_type
+ #if N > 0
+ template<typename Context>
+ struct callable_context_wrapper<Context, N>
+ : remove_cv<Context>::type
{
- inner_context();
- struct private_type_ { private_type_ const &operator,(int)
const; };
+ callable_context_wrapper();
typedef private_type_ const
&(*pointer_to_function)(BOOST_PP_ENUM_PARAMS(BOOST_PP_INC(ARG_COUNT),
detail::dont_care BOOST_PP_INTERCEPT));
operator pointer_to_function() const;
};
+ #endif
+
+ template<typename Expr, typename Context>
+ struct is_expr_handled<Expr, Context, N>
+ {
+ static callable_context_wrapper<Context, ARG_COUNT> &sctx_;
+ static Expr &sexpr_;
+
+ BOOST_STATIC_CONSTANT(bool, value =
+ (
+ sizeof(yes_type) ==
+ sizeof(
+ detail::check_is_expr_handled(
+ (sctx_(
+ typename Expr::proto_tag()
+ BOOST_PP_ENUM_TRAILING(ARG_COUNT,
BOOST_PROTO_ARG_N, sexpr_)
+ ), 0)
+ )
+ )));
+
+ typedef mpl::bool_<value> type;
+ };
+ }
- public:
+ template<typename Expr, typename Context>
+ struct callable_eval<Expr, Context, N>
+ {
typedef
typename boost::result_of<
Context(
@@ -109,39 +147,11 @@
result_type operator ()(Expr &expr, Context &context) const
{
- BOOST_STATIC_CONSTANT(bool, value =
- (
- sizeof(yes_type) ==
- sizeof(
- callable_eval::check(
- (static_cast<inner_context
&>(const_cast<context_type &>(context))(
- typename Expr::proto_tag()
- BOOST_PP_ENUM_TRAILING(ARG_COUNT,
BOOST_PROTO_ARG_N, expr)
- ), 0)
- )
- )));
- return (*this)(expr, context, mpl::bool_<value>());
- }
-
- private:
-
- typedef char yes_type;
- typedef char (&no_type)[2];
- template<typename T> static yes_type check(T const &);
- static no_type check(typename inner_context::private_type_ const
&);
-
- result_type operator ()(Expr &expr, Context &context, mpl::true_)
const
- {
return context(
typename Expr::proto_tag()
BOOST_PP_ENUM_TRAILING(ARG_COUNT, BOOST_PROTO_ARG_N, expr)
);
}
-
- result_type operator ()(Expr &expr, Context &context, mpl::false_)
const
- {
- return default_eval<Expr, Context>()(expr, context);
- }
};
#undef N
Index: default.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/xpressive/proto/context/default.hpp,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -d -r1.1 -r1.2
--- default.hpp 23 Jun 2007 21:22:31 -0000 1.1
+++ default.hpp 1 Jul 2007 07:43:05 -0000 1.2
@@ -62,7 +62,6 @@
namespace boost { namespace proto
{
-
template<typename Expr, typename Context, typename Tag = typename
Expr::proto_tag, long Arity = Expr::proto_arity::value>
struct default_eval
{};
@@ -336,9 +335,9 @@
{
/// default_context::eval
///
- template<typename Expr>
+ template<typename Expr, typename ThisContext = default_context
const>
struct eval
- : default_eval<Expr, default_context const>
+ : default_eval<Expr, ThisContext>
{};
};
Index: null.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/xpressive/proto/context/null.hpp,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -d -r1.1 -r1.2
--- null.hpp 25 Jun 2007 07:44:54 -0000 1.1
+++ null.hpp 1 Jul 2007 07:43:05 -0000 1.2
@@ -53,9 +53,9 @@
{
/// null_context::eval
///
- template<typename Expr>
+ template<typename Expr, typename ThisContext = null_context const>
struct eval
- : null_eval<Expr, null_context const>
+ : null_eval<Expr, ThisContext>
{};
};
-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Boost-cvs mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/boost-cvs
