rust/tests/ui/self/where-for-self.rs

54 lines
916 B
Rust

//@ run-pass
// Test that we can quantify lifetimes outside a constraint (i.e., including
// the self type) in a where clause.
// FIXME(static_mut_refs): this could use an atomic
#![allow(static_mut_refs)]
static mut COUNT: u32 = 1;
trait Bar<'a> {
fn bar(&self);
}
trait Baz<'a>
{
fn baz(&self);
}
impl<'a, 'b> Bar<'b> for &'a u32 {
fn bar(&self) {
unsafe { COUNT *= 2; }
}
}
impl<'a, 'b> Baz<'b> for &'a u32 {
fn baz(&self) {
unsafe { COUNT *= 3; }
}
}
// Test we can use the syntax for HRL including the self type.
fn foo1<T>(x: &T)
where for<'a, 'b> &'a T: Bar<'b>
{
x.bar()
}
// Test we can quantify multiple bounds (i.e., the precedence is sensible).
fn foo2<T>(x: &T)
where for<'a, 'b> &'a T: Bar<'b> + Baz<'b>
{
x.baz();
x.bar()
}
fn main() {
let x = 42;
foo1(&x);
foo2(&x);
unsafe {
assert_eq!(COUNT, 12);
}
}