[Bug c++/64870] value not set via reference

["conradsand.arma at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64870

--- Comment #4 from Conrad <conradsand.arma at gmail dot com> ---
(In reply to Marc Glisse from comment #3)
> 
> Except when there is an = sign, where you expect the right hand side to be
> evaluated before the left? And maybe a few other cases?

For iostreams which use the << operator for printing, the expected order is to
print things left-to-right, and hence evaluate left-to-right.

> > What is the benefit in changing the expected order of evaluation?
> 
> Performance.

Is there a benchmark to support the re-ordering?  If we're talking 1%-2% here
and there, is this really worth the "wtf" moments?