Killing equals_t

[bearophile]

Jonathan M Davis:

> (since D1 made the mistake of having opEquals return int),

I think it wasn't a mistake, more like a design choice. In some 
cases (especially when there is no inlining) computing and 
returning an int is more efficient than converting to bool.

In practice I think the increase in performance is not 
significant with modern compilers, and I prefer the clarity of a 
bool result.

Bye,
bearophile