In this respect, they share the characteristic of being easy to wholly disable (i.e. prevent them from being compiled at all). With pre & post conditions if the

In this respect, they share the characteristic of being easy to wholly disable (i.e. prevent them from being compiled at all). With pre & post conditions if the var `clojure.core/assert` is bound to false, then they're elided. The usual pattern is to have them on for testing, and disable when compiling for production.