On Tuesday, 11 September 2012 at 19:03:56 UTC, Namespace wrote:
I think it is UB rather than a bug. The spec says that return
types must match exactly. AFAIK auto is a feature to infer
return type, not to magically adjust to multiple incompatible
types.
But i thought Variant is one. ;)
I guess (never used Variant) that it uses templated getter which
correctly returns value. Float values are returned in %xmm
registers and integer values are returned in %eax. Without
knowing return type a caller doesn't know where to take return
value. For example in this case foo function correctly places
return values, but main takes in both cases return value from
%xmm.
