This is an assertion that is always enabled. If the test is false, it will print any supplied error message to stderr and raise an error.
primitive val Fact
new val create() : Fact val^
fun box apply( test: Bool val, msg: String val = "") : None val ?
fun box eq( that: Fact val) : Bool val
fun box ne( that: Fact val) : Bool val
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© 2014-2015, Causality Ltd.
Licensed under the BSD 2-Clause License.
https://stdlib.ponylang.io/assert-Fact