On Thu, 09 Sep 2010 06:08:14 -0400, Eldar Insafutdinov
<[email protected]> wrote:
A while back dmd stopped allowing rvalues as ref function arguments. I
entirely understand why it was done, but the same restriction applies to
the
ref const function parameters. This causes a lot of pain and at the
moment
makes me use pass-by-value parameters(most notably when using structs).
C++
doesn't have any problem with const ref and rvalues. Can we please
restore
this behavior for const ref?
auto ref is supposed to handle that. However, I think it only works on
templates.
The thing is, when you pass an rvalue by reference, it's more expensive
than passing it by value. If passed by value, since it's an rvalue, the
compiler knows that it no longer is needed elsewhere, so it can just store
it on the stack in the place it will be passing it.
I still think the design needs some work, and there are some compiler
annoyances that can't be helped (like the compiler complaining that
opEquals must take const ref T) that make it impossible to write correct
code.
-Steve
