On Fri, 01 Mar 2013 18:35:43 -0500, Namespace
<[email protected]> wrote:
At least I have noticed so far, that you're in any case for
something like const&. Accordingly, you answer my question
with 'yes, we need something like this.'.
On Friday, 1 March 2013 at 23:46:36 UTC, Steven Schveighoffer
wrote:
I would say yes, we need something like rvalue references to
avoid copy-paste hell. const& is not a good way to describe
it, because it implies const, which this problem does not
require.
This is the major problem that Andrei had with it (at least as
I understand his past statements) -- it conflates const with
rvalue references. Sometimes, you want a const ref that does
NOT bind to an rvalue.
If I have a medium sized struct that I only intend to
read/reference from I see no reason not to use 'const ref' for
simplicity and speed (and avoid postblit hopefully) but when it's
an Rvalue I need to make a second function either duplicate
except signature or forwarding the value.
The one huge problem I've had with lack of rvalue references is
with arithmetic operators:
struct M
{
M opAdd(const ref M other) const {...}
}
M m;
auto m2 = (m + m) + m; // ok!
auto m3 = m + (m + m); // error!
This is crap.
If 'auto ref' gets accepted for non-template functions, it goes
away. With M as you show, returning ref doesn't work so that
example I was going to suggest doesn't work.
