Add GC-free closures to D, similar to the ones C++ has

[Kagamin]

On Thursday, 5 September 2019 at 14:50:31 UTC, James Lu wrote:
> The first question should be, does the current closure 
> semantics support GC-free deallocation?

AFAIK, closure is allocated with _d_allocatememory hook. If you 
override it, you can use your preferred allocator there.