Different function attributes between debug and release build

[Lodovico Giaretta via Digitalmars-d]

Currently, std.string.assumeUTF is inferred @nogc in release 
mode, while in debug mode it isn't. Should this be allowed?
It can cause some problems, e.g. I have some @nogc unittests that 
I use to guarantee that my code is in fact @nogc, and these fail 
because in debug mode assumeUTF is not.
In general (IMHO) this kind of difference should be avoided, 
because code should not change meaning between debug and release 
modes.

What do you think?