Emplacement in D

["Nordlöw"]

After having read about 
http://dlang.org/phobos/std_conv.html#.emplace

I wonder: Considering the fact that D has stricter control over 
memory, couldn't the need for emplace be removed through clever D 
compiler optimization when for example adding structs at the end 
of an array and assuming its constructor is safe?

At least If all the members recursively have value semantics it 
would be obvious right? But maybe that is a corner case.