OK,

This fix worked for me in clearing the issue around has_binary. However, I'm
still having a problem. The module I'm trying to build is an objective-c++
framework and, due to an earlier problem around anonymous enumerations, I
was told to use a later version of GCC than Apple's provided version. For
this reason I configured GCC 4.8.2 from MacPorts and set up a compiler
plug-in for Xcode 4.6 to build my framework using this version of the
compiler. I now appear to be in a Catch 22 scenario as GCC 4.8 apparently
does not support C blocks, giving me the following first error:

NSTask.h:69: Expected unqualified-id before '^'

I can clear this by reverting to Apple's GCC 4.2, but then I'll get
anonymous enum errors in Boost's decay.h.

I'm now way out of my depth and experience, so can anybody please offer any
help out of my dilemma?

Best wishes.
Tim Burgess