DIP 1016--ref T accepts r-values--Community Review Round 1
Petar
Petar
Fri Jul 20 10:33:31 UTC 2018
On Friday, 20 July 2018 at 10:08:03 UTC, Dgame wrote:
> On Friday, 20 July 2018 at 09:39:47 UTC, Nicholas Wilson wrote:
>> On Friday, 20 July 2018 at 09:03:18 UTC, Dukc wrote:
>>> appending something (like .byRef or byRef!long, the latter
>>> making an implicit type conversion)
>>
>> That can't work: either it returns an expired stack temporary
>> (*very* bad), or allocates with no way to deallocate (bad).
>
> What about something like this?
>
> ----
> import std.stdio;
>
> ref T byRef(T)(T value) {
> static T _val = void;
> _val = value;
>
> return _val;
> }
>
> void foo(ref int a) {
> writeln("A = ", a);
> }
>
> void main() {
> foo(42.byRef);
> foo(23.byRef);
> }
> ----
Perhaps semantically correct, but practically a non-starter, due
to the performance implications of loading and storing to
thread-local storage and by extension the severe impact on
compiler optimizations. And also syntactically ugly, even if you
shorten it to something like `1.r`.
Anyway, I think the DIP is the best way forward - just remove the
stupid and unnecessary restriction.
More information about the Digitalmars-d
mailing list