auto ref

[KennyTM~]

On Dec 16, 09 15:18, Walter Bright wrote:
> There's a need in generic code to have a function take a parameter by
> ref if it is an lvalue, and by value if it is an rvalue. This can be
> addressed by making it a template using auto ref:
>
> T foo(T)(auto ref T x) { ... }
>
> foo(3) // call by value
> int y;
> foo(y) // call by reference
>
> There is also a need to 'transmit' the ref'ness to the return value.
> This can be done with auto ref:
>
> auto ref foo(T)(auto ref T x) { return x; }
>
> foo(3) => int foo(int x)
> foo(y) => ref int foo(ref int x)
>
> This means that the generic forwarding function would look like:
>
> auto ref foo(alias F, T...)(auto ref T args) { return F(args); }

auto const?