On Saturday, March 07, 2015 17:20:49 Timothee Cour via Digitalmars-d-learn wrote: > To clarify, I'm only asking about a struct allocated via new. > Unique!T is wrapped around a struct, but it allocates a struct T via 'new', > so my question still holds: does 'delete t' (where t is a struct allocated > via new) guarantee deterministic destruction? > > I'm guessing yes, otherwise Unique would be broken, but where is that > specified in the docs? > And if delete is to be deprecated (according to the docs), what is the > correct way to do that (despite fact that Unique relies on delete).
Yes, delete is deterministic. It's basically the same as what you get in C++ except that it's using the GC heap and therefore is not safe. delete is supposed to have been deprecated but has not been yet (mostly because no one has gotten around to doing it). If you're using the GC heap and want to destroy an object, that's what destroy is for - but it doesn't free the memory, because that's not safe. You can free the memory with core.memory.GC.free, but you have to have destroyed the object first, since free just frees memory. But that's just duplicating what delete does, so it's still unsafe. What's generally considered the correct way to deal with manual memory management involves allocating using C's malloc, constructing via emplace, and then using destroy and C's free to destroy the object and free its memory when you're done. But that's way more of a pain then using new and then delete, which is probably part of why some folks still use delete (in the case of Unique though, I expect that it's just because it's been around a while). Hopefully, the standard allocator stuff will make it as simple as using new and delete though - e.g. something like auto ptr = alloc.make!Myobj(arg1, arg2); alloc.free(ptr); but the standard allocator stuff isn't currently far enough along yet for us to be at that point unfortunately. - Jonathan M Davis
