`assert(false)` is pronounced "this can never happen." It's reasonable to add a comment with /why/ this can never happen, but if that's all the comment would have said, a message adds no value.

Oh I agree, literally `assert(false, "This cannot happen")` is useless, but ensuring message is always there encourages something more like, `assert(false, "This implies the Foo is Barred, but we have the Qux to make sure it never is")`.

Ensuring a message encourages people to state the assumptions that are violated, rather than just asserting that their assumptions (which?) don't hold.

what language are we talking about? If it's cpp then the pronounciation depends on compiler flags (perhaps inferred from CMAKE_BUILD_TYPE)

Swap the parameters around for C++ and similar langs where `assert(a, b)` evaluates the same as `(void) a; assert(b)`.