assert_exn : ('a -> bool) -> 'a -> exn -> 'a
assert_exn p x e returns x if the application p x evaluates to true. Otherwise, assert_exn p x e raises e
assert_exn p x e fails with exception e if the predicate p yields false when applied to the value x. If the application p x raises an exception ex, then assert_exn p x e raises ex.
- null []; > val it = true : bool - assert_exn null ([]:int list) (Fail "non-empty list"); > val it = [] : int list - null [1]; > false : bool - assert_exn null [1] (Fail "non-empty list");; ! Uncaught exception: ! Fail "non-empty list"