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#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
// Check a number of scenarios in which one impl tries to override another,
// without correctly using `default`.
// Test 1: one layer of specialization, multiple methods, missing `default`
trait Foo {
fn foo(&self);
fn bar(&self);
}
impl<T> Foo for T {
fn foo(&self) {}
fn bar(&self) {}
}
impl Foo for u8 {}
impl Foo for u16 {
fn foo(&self) {} //~ ERROR E0520
}
impl Foo for u32 {
fn bar(&self) {} //~ ERROR E0520
}
// Test 2: one layer of specialization, missing `default` on associated type
trait Bar {
type T;
}
impl<T> Bar for T {
type T = u8;
}
impl Bar for u8 {
type T = (); //~ ERROR E0520
}
// Test 3a: multiple layers of specialization, missing interior `default`
trait Baz {
fn baz(&self);
}
impl<T> Baz for T {
default fn baz(&self) {}
}
impl<T: Clone> Baz for T {
fn baz(&self) {}
}
impl Baz for i32 {
fn baz(&self) {} //~ ERROR E0520
}
// Test 3b: multiple layers of specialization, missing interior `default`,
// redundant `default` in bottom layer.
trait Redundant {
fn redundant(&self);
}
impl<T> Redundant for T {
default fn redundant(&self) {}
}
impl<T: Clone> Redundant for T {
fn redundant(&self) {}
}
impl Redundant for i32 {
default fn redundant(&self) {} //~ ERROR E0520
}
fn main() {}
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