Subject: [Boost-commit] svn:boost r55491 - trunk/libs/spirit/example/karma
From: hartmut.kaiser_at_[hidden]
Date: 2009-08-09 15:01:37
Author: hkaiser
Date: 2009-08-09 15:01:36 EDT (Sun, 09 Aug 2009)
New Revision: 55491
URL: http://svn.boost.org/trac/boost/changeset/55491
Log:
Spirit: another fix to the calc2_ast_vm example
Text files modified:
trunk/libs/spirit/example/karma/calc2_ast_vm.hpp | 74 ++++++---------------------------------
1 files changed, 12 insertions(+), 62 deletions(-)
Modified: trunk/libs/spirit/example/karma/calc2_ast_vm.hpp
==============================================================================
--- trunk/libs/spirit/example/karma/calc2_ast_vm.hpp (original)
+++ trunk/libs/spirit/example/karma/calc2_ast_vm.hpp 2009-08-09 15:01:36 EDT (Sun, 09 Aug 2009)
@@ -81,6 +81,18 @@
{
return boost::get<T>(expr.expr);
}
+
+ // the specialization below tells Spirit to handle expression_ast as if it
+ // where a 'real' variant
+ namespace spirit { namespace traits
+ {
+ template <typename T>
+ struct not_is_variant;
+
+ template <>
+ struct not_is_variant<expression_ast>
+ : mpl::false_ {};
+ }}
}
enum byte_code
@@ -164,66 +176,4 @@
boost::phoenix::function<unary_expr<op_pos> > pos;
boost::phoenix::function<unary_expr<op_neg> > neg;
-///////////////////////////////////////////////////////////////////////////////
-// A couple of phoenix functions helping to access the elements of the
-// generated AST
-///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-struct get_element
-{
- template <typename T1>
- struct result { typedef T const& type; };
-
- T const& operator()(expression_ast const& expr) const
- {
- return boost::get<T>(expr.expr);
- }
-};
-
-boost::phoenix::function<get_element<int> > _int;
-boost::phoenix::function<get_element<binary_op> > _bin_op;
-boost::phoenix::function<get_element<unary_op> > _unary_op;
-
-///////////////////////////////////////////////////////////////////////////////
-struct get_left
-{
- template <typename T1>
- struct result { typedef expression_ast const& type; };
-
- expression_ast const& operator()(binary_op const& bin_op) const
- {
- return bin_op.left;
- }
-};
-
-boost::phoenix::function<get_left> _left;
-
-struct get_right
-{
- template <typename T1>
- struct result { typedef expression_ast const& type; };
-
- template <typename Node>
- expression_ast const& operator()(Node const& op) const
- {
- return op.right;
- }
-};
-
-boost::phoenix::function<get_right> _right;
-
-struct get_op
-{
- template <typename T1>
- struct result { typedef int type; };
-
- template <typename Node>
- int operator()(Node const& bin_op) const
- {
- return bin_op.op;
- }
-};
-
-boost::phoenix::function<get_op> _op;
-
#endif