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|
// 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() { }
|
