Avoid GC with closures

[Dicebot via Digitalmars-d]

On 05/28/2016 09:58 PM, Iakh wrote:
> Yeah. It doesn't capture any context. But once it does it
> would be an error.

Custom allocators are not very suitable for things like closures because
of undefined lifetime. Even if it was allowed to replace allocator, you
would be limited to either GC or RC based one anyway to keep things @safe.