On 5/5/13 7:55 AM, Timon Gehr wrote:
I still think auto ref should be extended to work for non-templated
functions. The semantics should be the same (i.e. behave as if there
were two copies that are eagerly semantically analyzed, but only
generate code for one) where possible. It would be an error to have
different behaviour of the two "copies". This would mean that in
non-templated functions, it should be an error to rely on whether or not
the passed argument was an lvalue. i.e. (auto) ref return of an auto ref
argument (at least in @safe code) and __traits(isRef,autoRefArgument)
should be disallowed. This would have the effect of making it illegal to
return references to temporaries from functions (at least in @safe
code), and hence the life time of rvalues would not have to be changed.
Both (1) and (2) would be close to non-issues with this solution.
I think the same. For non-templates "auto ref" should simply accept
rvalues and lvalues alike. Inside the function an "auto ref" parameter
is handled as a local (i.e. disappears at the end of the function) so
the compiler disallows returning it by reference directly with the
current algorithms. For more complicated patterns, dynamic checking will
pick the slack.
I'll think I'll rework my DIP for that.
Andrei
