http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47628
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-02-07 17:03:01 UTC --- btw, your analysis at http://article.gmane.org/gmane.comp.lib.boost.devel/214412 is bogus There is no C++99, presumably you mean C++98 C++0x mode is absolutely not the default mode of either g++ or libstdc++, I don't know what gave you that idea. The Boost.Signals code is ambiguous with or without C++0x mode enabled, although there is an extra ambiguity with C++0x mode I believe the underlying problem is that stored_group has a "catch all" constructor, which means that the conversion from non-const iterator to const_iterator is not better than the conversion from non-const iterator to key_type (i.e. stored_group) You should try this (untested) alternative fix, which should work for C++03 and C++0x, and looks like an improvement anyway: --- boost/signals/detail/named_slot_map.hpp.orig 2011-02-07 17:01:46.297942798 +0000 +++ boost/signals/detail/named_slot_map.hpp 2011-02-07 17:01:47.665572465 +0000 @@ -35,7 +35,7 @@ stored_group(storage_kind kind = sk_empty) : kind(kind), group() { } template<typename T> - stored_group(const T& group) : kind(sk_group), group(new T(group)) { } + explicit stored_group(const T& group) : kind(sk_group), group(new T(group)) { } bool is_front() const { return kind == sk_front; } bool is_back() const { return kind == sk_back; }
