On Sunday, 27 May 2018 at 22:27:52 UTC, sarn wrote:
I've been thinking this through a bit, and here's what I've got so far:
Here's a tweak that should be implementable without any language changes:
Instead of trying to detect an empty destructor, we use a UDA on the class --- call it BaseObject or something. A BaseObject-marked class is meant to be something like Andre's ProtoObject, or a custom alternative base. It must not define a destructor or include members with destructors (could relax this in future but works for now), and must only inherit from other BaseObject-marked classes.
With that, __vdtor could be implemented using a template mixin. For a BaseObject class, that would generate an empty virtual __vdtor. For other classes, it would call __xdtor and then (non-virtually) call __vdtor for the superclass as long as it's not a BaseObject class.
Can anyone see something I've missed? I think it works with the current type system, makes Andre's ProtoObject possible while supporting subclassing with @nogc or whatever, and gives us safe class destructors that could be compatible with C++.
