mozilla/rust — Issue #1883: Error message when a non-pure function is used as a constraint could be clearer
Author: bzbarsky
Created: 2012-02-22 17:38:26+00:00
State: open

Testcase:

fn foo() -> bool { true }
fn bar() : foo() {}

I get this error message: "error: Non-predicate in constraint: foo"

It would be nice if it just said something like "foo is not a pure function" instead.