rust/tests/ui/lub-glb/old-lub-glb-hr-noteq1.rs
2024-02-16 20:02:50 +00:00

30 lines
1.0 KiB
Rust

// Test taking the LUB of two function types that are not equatable but where one is more
// general than the other. Test the case where the more general type (`x`) is the first
// match arm specifically.
//@ revisions: leak noleak
//@[noleak] compile-flags:-Zno-leak-check
fn foo(x: for<'a, 'b> fn(&'a u8, &'b u8) -> &'a u8, y: for<'a> fn(&'a u8, &'a u8) -> &'a u8) {
// The two types above are not equivalent. With the older LUB/GLB
// algorithm, this may have worked (I don't remember), but now it
// doesn't because we require equality.
let z = match 22 {
0 => x,
_ => y,
//[leak]~^ ERROR `match` arms have incompatible types
//[noleak]~^^ ERROR mismatched types
};
}
fn foo_cast(x: for<'a, 'b> fn(&'a u8, &'b u8) -> &'a u8, y: for<'a> fn(&'a u8, &'a u8) -> &'a u8) {
// But we can *upcast* explicitly the type of `x` and figure
// things out:
let z = match 22 {
0 => x as for<'a> fn(&'a u8, &'a u8) -> &'a u8,
_ => y,
};
}
fn main() {}