Low-Lock Singletons In D

[bearophile]

Max Samukha:

> Note that the Nullable is not phobos Nullable -
> the latter incurs unnecessary overhead for types that are 
> already nullable.

In Bugzilla I have suggested some improvements for Nullable, but 
in Phobos there is already an alternative Nullable that avoids 
that overhead:

struct Nullable(T, T nullValue);

Bye,
bearophile