Constructing a class in-place

[Kagamin]

On Thursday, 26 July 2018 at 12:45:52 UTC, Johan Engelen wrote:
> Thanks for pointing to D's placement new. This is bad news for 
> my devirtualization work; before, I thought D is in a better 
> situation than C++, but now it seems we may be worse off.

Just say that devirtualization is incompatible with 
method-changing reemplace. I don't think this imposes notable 
portability restrictions.