On Saturday, 6 June 2015 at 18:32:14 UTC, Meta wrote:
On Saturday, 6 June 2015 at 06:59:26 UTC, Jonathan M Davis
wrote:
That being said, we really should find a way to make it so
that lambda's don't turn into delegates unless they really
need to. In many, many cases, they should be plenty efficient
without having to force the issue with functors, but they
aren't, because we allocate for them unnecessarily. I don't
know how easy it'll be though for the compiler devs to figure
out how to optimize that, since sometimes you _do_ need to
allocate a closure.
int n = 2;
auto r1 = [1, 2, 3].map!(x => x + n); //Ok
auto r2 = [1, 2, 3].map!(function(x) => x + n); //Error
auto r3 = [1, 2, 3].map!(curry!(function(x, n) => x + n, n));
//Ok
IMO this is pretty much the same thing as copying the variables
you want to close over into a struct, with the advantage that
we can do it today. The only thing is that you have to specify
which variables you want to copy, which isn't necessarily a bad
thing.
And apparently curry actually allocates a closure. Nevermind
that, then.
