Clojurians Log v2

what is the rationale behind making vswap! a macro instead of a function like vreset! or swap! ?

it seems that macro can be written as a function, and all it does is... double-evaluates the volatile arg expr

Probably performance? Volatiles are designed to be as fast as possible short of an actual local). Even a let binding to guarantee single-eval would compromise that

there is no "double eval" here