safe pure unittest

[Dicebot via Digitalmars-d-learn]

On Wednesday, 13 August 2014 at 12:26:02 UTC, simendsjo wrote:
> This is the first time I've seen attributes on unittests:
> https://github.com/D-Programming-Language/phobos/pull/2349/files#diff-ba05e420ac1da65db044e79304d641b6R179
>
> Has this always been supported? I guess it's good practice to 
> add these
> on unittests too, but does people even know about this feature? 
> And are
> there any cons to doing this?

unittest block is effectively just a special function declaration 
so all function attributes are applicable and act in a similar 
way.

It is an extremely important idiom when you wan't to ensure 
specific properties of templated function that may be valid or 
not depending on template arguments. For example, function with 
output range may be @nogc or not depending if used output range 
type triggers GC. But you can mark with @nogc unittest that uses 
it with dummy output range to ensure that _nothing else_ 
allocated.