Struct default constructor - need some kind of solution for C++ interop

[Ethan Watson via Digitalmars-d]

On Thursday, 8 September 2016 at 11:18:12 UTC, Walter Bright 
wrote:
> The thing is, the 'destroy()' function is going to swamp any 
> extra clock cycle, as will a virtual lookup and dereference.

Assume destroy() is a more trivial function then. The point is 
that if you put more than two branches in a 64-byte cacheline on 
that processor, things get significantly slower and the loop 
iteration itself becomes a hotspot.

Being D though. Destructors can be contracted, yeah? Because the 
way we operate is that we compile out all those validation checks 
for a retail release and assume everything works. Checking for 
the validity of the pointer in an in block would be perfect for 
that.