On 2010-08-10 17:23:39 -0400, foobar <[email protected]> said:
Steven Schveighoffer Wrote:
That doesn't help. deterministic destruction is not a struct-vs-class
problem, its a GC-vs-manual-memory problem. A struct on the heap that is
finalized by the GC has the same issues as a class destructor. In fact,
struct destructors are not currently called when they are heap-allocated
because the GC has no idea what is stored in those memory locations.
-Steve
Let me add to the above, that the GC should NOT manage structs
allocated on the heap. structs should only provide deterministic
semantics.
That's an interesting idea. By allowing classes only on the
garbage-collected heap, and structs only in non-garbage-collected
situations, we do indeed simplify the destructor problem. A struct
destructor is always deterministic and a class destructor is not.
Unfortunately, that's not exactly where things are headed.
I'm not sure what's best, but I'm starting to believe that without this
simple rule we'll have to add the complexity of having two kind of
destructors in the language... would this make sense:
class Test {
~this()
{
// disposer destructor
// called by deterministic destruction
// can access GC-managed members safely
}
~~this()
{
// finalizer destructor
// called during garbage collection
// cannot access GC-managed members (might be dangling
pointers)
// unavailable in SafeD because of the dangling pointers
}
}
--
Michel Fortin
[email protected]
http://michelf.com/
