Cannot make my shared PureMallocator callable in pure functions

[Nordlöw via Digitalmars-d-learn]

I'm struggling with making

https://github.com/nordlow/phobos-next/blob/master/src/pure_mallocator.d

callable in pure functions such as here

https://github.com/nordlow/phobos-next/blob/master/src/pure_mallocator.d#L84

Shouldn't a shared

    static shared PureMallocator instance;

make it possible to call

    PureMallocator.instance.allocate(16);

in pure functions?