Why do we have transitive const, again?

[bearophile]

Timon Gehr:

> I think it should be a language feature, as proposed by Jonathan.

I did miss his post. I see he has turn that idiom into a language feature :-)

>From Jonathan's post:

> 2. __varLoaded is default-initialized to false, and __var is void (so, garbage).

The GC has to read __varLoaded and then scan the contents of __var only if __varLoaded is true.

To do this in user code (or code rewritten by front-end rules) time ago I have suggested to add this simple standard method to D:

bool onGC(string fieldName)() {...}

That if present is called by the GC during its scan, to know if a union/struct/clas method needs to be scanned now (I did invent it for unions, but it's useful for structs too, it seems).

Bye,
bearophile