Const ref and rvalues again...

[martin]

On Thursday, 8 November 2012 at 22:34:03 UTC, Timon Gehr wrote:
> Ambiguous to me and all the interpretations are either wrong or 
> irrelevant.

My point is that it may affect performance. If there was no 
const, the compiler would need to allocate a dedicated copy of a 
literal whenever passing it to a mutable ref parameter unless the 
optimizer worked so well it can prove it's not going to be 
modified (which I'm sure you'd expect though :D).

> Maybe you should stop trying to show that 'const' is sufficient 
> for resolving those issues. The point is that it is not 
> _necessary_. It is too strong.

In that case it actually is - who cares if the read-only double 
rvalue the function is passed is the result of an implicit cast 
(and there's a reason for it being implicit) of the original 
argument (int rvalue)?

Anyway, I think we have moved on in this thread, so maybe you 
could contribute to trying to settle this rvalue => (const) ref 
issue once and for all by commenting my latest proposal.