Subject: [Boost-commit] svn:boost r74053 - trunk/boost/spirit/home/support
From: hartmut.kaiser_at_[hidden]
Date: 2011-08-24 18:22:05
Author: hkaiser
Date: 2011-08-24 18:22:04 EDT (Wed, 24 Aug 2011)
New Revision: 74053
URL: http://svn.boost.org/trac/boost/changeset/74053
Log:
Spirit: adding attribute collapsing for optional<optional<>>
Text files modified:
trunk/boost/spirit/home/support/attributes.hpp | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
Modified: trunk/boost/spirit/home/support/attributes.hpp
==============================================================================
--- trunk/boost/spirit/home/support/attributes.hpp (original)
+++ trunk/boost/spirit/home/support/attributes.hpp 2011-08-24 18:22:04 EDT (Wed, 24 Aug 2011)
@@ -119,7 +119,7 @@
// // An exposed attribute is a weak substitute for a supplied container
// // attribute if it is a weak substitute for its value_type. This is
-// // true as all character parsers exposing compatible with a container
+// // true as all character parsers are compatible with a container
// // attribute having the corresponding character type as its value_type.
// template <typename T, typename Expected>
// struct is_weak_substitute_for_value_type
@@ -604,6 +604,12 @@
typedef boost::optional<T> type;
};
+ template <typename T>
+ struct build_optional<boost::optional<T> >
+ {
+ typedef boost::optional<T> type;
+ };
+
template <>
struct build_optional<unused_type>
{