http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58093
--- Comment #5 from Nick Maclaren <nmm1 at cam dot ac.uk> --- I did. Please read what the C++ standard says about conversions. 4.7 [conv.integral] paragraph 2 is a paraphrase of wording that has been in every C and C++ compiler since C90, and states that all integers (negative and positive) can be represented in unsigned ones of an equal or greater rank. Indeed, this was and is a design requirement in the parts of the library that use -1 converted to an unsigned integer as a result type. I can't be bothered to pursue this one further - as I said, one more confusing diagnostic is neither here nor there.
