On Thursday, 20 September 2012 at 08:10:36 UTC, Namespace wrote:
You're right.
This is my next try: http://dpaste.dzfl.pl/02b32d33
Do you have anything else to say? :)
I think it looks good, but I'm unsure about "move", or allowing
pass by value:
Classes can't be memcopied the way structs can: Class may have
default constructors, or copy constructors, which would be
totally ignored by a memcopy. For example, if your class had a
"RefCounted" member, its postblit would never be called, and it
would then be "over destroyed":
--------
class A
{
RefCounted!int rf;
this()
{
rf.RefCounted.ensureInitialized();
rf = 5;
}
}
void main()
{
A a = new A();
OnStack!A osa = OnStack!A.move(a);
}
--------
core.exception.InvalidMemoryOperationError
--------
Here, osa makes a binary copy of the RefCounted, so the count
stays at 1.
Then, when osa is destroyed, it deletes the RefCounted's store.
However, when a is destroyed, it still has a pointer to the
(deleted) store, creating the Error...
I think "move" has to go, because classes are just not moveable.
pass by value can stay, if and only if, T gives a copy
constructor. Or NO constructors (in which case a memcopy should
be the same as a default copy).
