DIP18: Non-GC threads

[bearophile]

Piotr Szturmaj:

> This is done by adding nogc attribute for functions. nogc 
> functions cannot perform operations that may allocate garbage 
> collected memory.

I suggest to call that @nogc.

Time ago I have suggested a "@noheap" attribute for functions, 
that is similar to that "nogc", see the discussion there:
http://d.puremagic.com/issues/show_bug.cgi?id=5219

The difference is that @noheap disallows C functions like C 
malloc(), etc. Stack allocation like alloca() and variable length 
arrays is allowed in @noheap functions.

@noheap/@nogc is probably inferred for templated functions, as 
pure/nothrow.

The main disadvantage of an annotation like this is the 
proliferation of kinds of functions. The advantage is a more 
precise control of the effects of functions.

The Koka language has a function annotation similar to @noheap, I 
have discussed a little about Koka here:
http://forum.dlang.org/thread/ocxmiolhlcysehbjtcop@forum.dlang.org
but Koka has type inference for effects, so often you don't need 
to add that annotation to functions.

Bye,
bearophile