> It is invalid to use sizeof() with a function
> type expression (C99 '6.5.3.4 para. 1) and hence this code invokes
> undefined behavior. gcc gives a warning if you compile with -pedantic,
> but otherwise it apparently just returns 1;
It's not quite that simple - look at footnote 84 :-(
Both function designators ('function names') and sizeof are weird,
in that they look like a value and a function, but aren't quite.
But this is actually a BUG in gcc - look at 5.1.1.3. The restriction
that sizeof may not have an argument that is function type is a
constraint, and therefore a breach requires a diagnostic.
Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email: nmm1@xxxxxxxxx
Tel.: +44 1223 334761 Fax: +44 1223 334679
