My advice on implementing stuff in C:

Ah yes, I forgot that ingenious example. However, my point stands: this is not a name lookup problem, it is a particularly ingenious use of the parsing rules around implicit int to produce radically different parse trees from nearly identical input (and by no means the only example: see Alexandrescu's wonderful code in _Modern C++ Design_ to execute arbitrary code at compile time via abuse of sizeof().)

But, yes, this sort of example is probably an indictment of C++. Clarity in coding this is not!