On 09/03/2013 03:22 PM, bearophile wrote:
> Currently this code doesn't work, because the B array is const, so B[i]
> is const:
>
>
> import std.algorithm: schwartzSort;
> void main() {
> auto A = [0, 1, 2];
> const B = [10, -20, 30];
> schwartzSort!(i => B[i])(A);
The return type of the lambda is deduced as const(int). I think that is
silly. A copied value type should not preserve the const attribute. (I
vaguely remember discussions on this topic.)
Explicit return type works:
schwartzSort!(delegate int (i) => B[i])(A);
Playing along with the compiler and casting away const also works:
schwartzSort!(i => cast()B[i])(A);
> }
>
>
> dmd gives:
>
> ...\dmd2\src\phobos\std\conv.d(3734): Error: static assert "Don't know
> how to emplace a const(int) with a const(int)."
> ...\dmd2\src\phobos\std\algorithm.d(9210): instantiated from
> here: emplace!(const(int), const(int))
> test.d(5): instantiated from here: schwartzSort!(__lambda2, "a <
> b", cast(SwapStrategy)0, int[])
>
>
> But the array A is mutable. So is it acceptable for me to ask in
> Bugzilla this code to work?
I would think so but I think this issue may already be in bugzilla.
>
> Bye,
> bearophile
Thanks,
Ali
