Kapps:
That code is not @nogc safe, as you're creating a dynamic array within it. The fact that LDC2 at full optimizations doesn't actually allocate is simply an optimization and does not affect the design of the code.
I've added the opposite of what you say in the DIP. So Walter can fix it if it's wrong, or leave it there if it's right, because that DIP can't miss to to specify one behavour or the other:
http://wiki.dlang.org/DIP60 Bye, bearophile
