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Rollup merge of #89588 - BoxyUwU:add_a_test_uwu, r=lcnr

Add a test for generic_const_exprs

Test that const_eval_resolve evaluates consts with unused inference vars in substs

r? ``@lcnr``
This commit is contained in:
Manish Goregaokar 2021-10-06 12:33:23 -07:00 committed by GitHub
commit eb7da35d84
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// run-pass
#![feature(generic_const_exprs)]
#![allow(incomplete_features)]
trait Foo<const N: usize> {
type Assoc: Default;
}
impl Foo<0> for () {
type Assoc = u32;
}
impl Foo<3> for () {
type Assoc = i64;
}
fn foo<T, const N: usize>(_: T) -> <() as Foo<{ N + 1 }>>::Assoc
where
(): Foo<{ N + 1 }>,
{
Default::default()
}
fn main() {
// Test that we can correctly infer `T` which requires evaluating
// `{ N + 1 }` which has substs containing an inference var
let mut _q = Default::default();
_q = foo::<_, 2>(_q);
}