On Thursday, May 10, 2018 06:31:09 Mike Franklin via Digitalmars-d-learn wrote: > On Thursday, 10 May 2018 at 06:22:37 UTC, Jonathan M Davis wrote: > > Structs don't have that. > > Should they?
Honestly, I don't think that classes should have it, but changing it now would break code (most notably, DWT). IMHO, it would have been far better to make it explicit like it is in C++, especially since there's no technical reason why it needs to be built in. But regardless, when you consider how structs work, having a nested struct inside a struct have a pointer to its outer struct would be a serious problem, because the pointer would become invalid as soon as the struct was moved, which happens quite frequently with structs in D when they're passed around. Having a nested struct within a class have a reference to its parent would be more debatable, but it would probably run afoul of how init works, since the init value for the struct would have to be known at compile-time, whereas the reference for the class couldn't be. And anyone who wants any kind of reference to the outer class to be in the struct can just pass it to the struct's constructor. Adding such a feature to structs would just be unnecessary magic. - Jonathan M Davis
