// Check that explicit region bounds are allowed on the various // nominal types (but not on other types) and that they are type // checked. struct Inv<'a> { // invariant w/r/t 'a x: &'a mut &'a isize } pub trait Foo<'a, 't> { fn no_bound<'b>(self, b: Inv<'b>); fn has_bound<'b:'a>(self, b: Inv<'b>); fn wrong_bound1<'b,'c,'d:'a+'b>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>); fn wrong_bound2<'b,'c,'d:'a+'b>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>); fn okay_bound<'b,'c,'d:'a+'b+'c>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>); fn another_bound<'x: 'a>(self, x: Inv<'x>, y: Inv<'t>); } impl<'a, 't> Foo<'a, 't> for &'a isize { fn no_bound<'b:'a>(self, b: Inv<'b>) { //~^ ERROR lifetime parameters or bounds on method `no_bound` do not match } fn has_bound<'b>(self, b: Inv<'b>) { //~^ ERROR lifetime parameters or bounds on method `has_bound` do not match } fn wrong_bound1<'b,'c,'d:'a+'c>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>) { //~^ ERROR method not compatible with trait //~| ERROR method not compatible with trait // // Note: This is a terrible error message. It is caused // because, in the trait, 'b is early bound, and in the impl, // 'c is early bound, so -- after substitution -- the // lifetimes themselves look isomorphic. We fail because the // lifetimes that appear in the types are in the wrong // order. This should really be fixed by keeping more // information about the lifetime declarations in the trait so // that we can compare better to the impl, even in cross-crate // cases. } fn wrong_bound2(self, b: Inv, c: Inv, d: Inv) { //~^ ERROR lifetime parameters or bounds on method `wrong_bound2` do not match the trait } fn okay_bound<'b,'c,'e:'b+'c>(self, b: Inv<'b>, c: Inv<'c>, e: Inv<'e>) { } fn another_bound<'x: 't>(self, x: Inv<'x>, y: Inv<'t>) { //~^ ERROR E0276 } } fn main() { }