bearophile wrote:
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
Thanks, I didn't know that. There are some good arguments for @nogc.
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.
I would prefer @nogc, because nogc functions can manually allocate. Not
using malloc, or preallocating using it is a lot easier than checking
for GC allocations and manually managing non-gc threads.
The main reason under @nogc is not non-deterministic allocation of GC or
malloc. The whole idea is to guarantee that nogc threads are not
suspended by the GC.
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 advantage is that you'd get the static checks similar to nothrow and
pure.
The Koka language has a function annotation similar to @noheap, I have
discussed a little about Koka here:
http://forum.dlang.org/thread/ocxmiolhlcysehbjt...@forum.dlang.org
but Koka has type inference for effects, so often you don't need to add
that annotation to functions.
Well, __traits(hasGCallocations, func) will also do the trick.
