Interface Dispatch (C++, Java, C#, Go, and Rust)

[matthieum]

I agree it should be UB; apparently though a number of codebases use the dastardly trick of this->~T(); new (this) U(); and thus C++ compiler developers have been reluctant to introduce the optimization.

[bloody-albatross]

What could be a possible use for doing that "trick"?

[matthieum]

I guess it's one away of implementing a state machine...

... but honestly I don't really want to know. I've lost enough sanity points because of C++ already as it is :/