// 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 second match arm specifically. // // FIXME(#73154) Pure NLL checker without leak check accepts this test. // (Note that it still errors in old-lub-glb-hr-noteq1.rs). What happens // is that, due to the ordering of the match arms, we pick the correct "more // general" fn type, and we ignore the errors from the non-NLL type checker that // requires equality. The NLL type checker only requires a subtyping // relationship, and that holds. To unblock landing NLL - and ensure that we can // choose to make this always in error in the future - we perform the leak check // after coercing a function pointer. // revisions: leak noleak //[noleak] compile-flags: -Zno-leak-check //[noleak] check-pass 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 => y, _ => x, //[leak]~^ ERROR `match` arms have incompatible 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() {}