incr.comp.: Maybe optimize case of dependency-less anonymous queries. (original) (raw)

Some kinds of queries can end up with no dependencies. That is a valid case if their computation solely depends on their query key and not on anything in the environment. erase_regions_ty is such a case.

We could optimize this case by not allocating a DepNode for such query invocations, which in turn would also save registering reads of that DepNode.

@nikomatsakis, should we do this? If so, I could write some mentoring instructions.