Is it possible to use an anonymous namespace declared in A.hxx and defined in A.cxx in B.cxx class?. As I understand, namespaces are applicable to that compilation unit alone and since there is no namespace name, we cannot use them in any other file.
Anonymous namespaces (and everything defined inside them) are only accessible from the file they are in. If you are wanting to know their use, a quick Google should help you, but here is a link to an the answer I found: http://stackoverflow.com/questions/5312213/uses-of-unnamed-namespace-in-c
Hope this helps.