// vim: tw=80
//! a method that uses unboxed trait object arguments
#![deny(warnings)]
use mockall::*;
#[automock]
trait Foo {
fn foo(&self, x: &dyn PartialEq<u32>);
}
// It's almost impossible to construct a Predicate object that will work with
// trait objects for two reasons:
// * Mockall requires the predicates to be Debug, and any useful predicate will
// also be Eq, Ord, or similar, but Rust only allows up to one non-auto trait
// per trait object.
// * The predicate is requird to meet the HRTB
// for<'a> Predicate<(dyn Trait + 'a)>
// That's not impossible, but Mockall doesn't provide any way to construct
// such a predicate.
// So, use of `with` is pretty much limited to predicates like `always` and
// `function`.
#[test]
fn with() {
let mut mock = MockFoo::new();
mock.expect_foo()
.with(predicate::always())
.return_const(());
mock.foo(&42u32)
}
/// trait object arguments can't be matched with `predicate::eq`, because
/// `PartialEq<Self>` cannot be made into a trait object. But withf still
/// works.
#[test]
fn withf() {
let mut mock = MockFoo::new();
mock.expect_foo()
.withf(|x| *x == 42u32)
.return_const(());
mock.foo(&42u32);
}