Daniel Frey wrote: > > The current version of the file type_with_alignment.hpp > gives spourios > > errors, because some macro expansion code generates '>>' > instead of '> > > > >>' (closing template brackets). The corresponding fixing patch is > > > > attached. > > Just out of curiousity: Is this a workaround for a compiler > bug? I think > I remember that if generated by the preprocessor, tokens need to be > glued with ## to form a single new token like >>, otherwise even two > consecutive >'s will be treated like two tokens. My colleague > says I'm > wrong. Am I? :)
Concatenating two tokens with the '##' operator, where the result isn't a new valid token results in undefined behaviour. In your sample it yields '>>', which is a valid token, so it is well defined. In other contexts two consecutive '>' characters are always interpreted as '>>' and not as two single '>'. But this isn't the point here. The '>>' was not formend by a '##' operator but by plain consecutiveness: #define SOME_MACRO(T) <T> SOME_MACRO(some_class<...>) // expands to <some_class<...>> But it should be <some_class<...> > Regards Hartmut _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
