Am 30.01.2017 um 22:03 schrieb Johannes Schindelin:
It is curious, though, that an expression like "sizeof(a++)" would not be rejected.
Clang normally warns about something like this ("warning: expression with side effects has no effect in an unevaluated context [-Wunevaluated-expression]"), but not if the code is part of a macro. I don't know if that's intended, but it sure is helpful in the case of SWAP.
Further, what would SWAP(a++, b) do? Swap a and b, and *then* increment a?
That might be a valid expectation, but GCC says "error: lvalue required as unary '&' operand" and clang puts it "error: cannot take the address of an rvalue of type".
René