rust/src/test/ui/lub-glb/old-lub-glb-hr-eq.rs
Niko Matsakis 6929013b85 fix subtle bug in NLL type checker
The bug was revealed by the behavior of the old-lub-glb-hr-noteq1.rs
test. The old-lub-glb-hr-noteq2 test shows the current 'order dependent'
behavior of coercions around higher-ranked functions, at least when
running with `-Zborrowck=mir`.

Also, run compare-mode=nll.
2020-06-22 18:51:08 +00:00

28 lines
824 B
Rust

// Test that we give a note when the old LUB/GLB algorithm would have
// succeeded but the new code (which requires equality) gives an
// error. However, now that we handle subtyping correctly, we no
// longer get an error, because we recognize these two types as
// equivalent!
//
// check-pass
fn foo(x: fn(&u8, &u8), y: for<'a> fn(&'a u8, &'a u8)) {
// The two types above are actually equivalent. With the older
// leak check, though, we didn't consider them as equivalent, and
// hence we gave errors. But now we've fixed that.
let z = match 22 {
0 => x,
_ => y,
};
}
fn foo_cast(x: fn(&u8, &u8), y: for<'a> fn(&'a u8, &'a u8)) {
let z = match 22 {
// No error with an explicit cast:
0 => x as for<'a> fn(&'a u8, &'a u8),
_ => y,
};
}
fn main() {}