On 2017-12-13 13:18, mrphobby wrote:
I have been taking a look at your example. Looks pretty neat! Some advanced mixin stuff there that looks pretty useful.
They're pretty basic ;)
However, as far as I can tell there is no handling of retain/release.
No, that's correct.
How would you incorporate this into your mixin system without having to put "release" in all the interface definitions?
You can add methods for retain/release in the ClassTrait template [1].
Would it be possible to somehow hook this up automatically to the D destructor perhaps? Interested in hearing your thoughts on this!
As far as I know, the destructor is only called (automatically by the GC). Since the Objective-C objects are not created using the GC the destructor will never be called. I don't think it's possible to implement reference counting (that would call retain/release) for classes in D, since it's not possible to overload the assignment operator for classes [2] or implement a postblit [3]. The only option, as far as I know, would be to wrap the class in a struct that calls retain/release automatically. But then you need to box/unbox the wrapped class constantly and all the method signatures would probably need to use this wrapper as well.
[1] https://github.com/jacob-carlborg/d_webkit_test/blob/master/source/foundation/util.d#L28
[2] https://dlang.org/spec/operatoroverloading.html#assignment [3] https://dlang.org/spec/struct.html#struct-postblit -- /Jacob Carlborg
