[Dlang-study] [lifetime] Local garbage collector for pure functions

[Marc Schütz]

This is a very nice idea. Note that LDC already transforms 
certain GC allocations into stack allocations, but only as an 
optimization. There need to be fixed rules about which kinds of 
allocations are guaranteed to be moved to the stack or a 
dedicated region allocator.

By the way, you seem to have in mind a special function 
attribute, but this isn't necessary. In fact, apart from making 
the function @nogc, how it allocates is memory is purely an 
implementation detail. Your suggestions therefore don't require 
(formal) purity or any special attribute in the function 
signature.