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// run-pass
#![allow(stable_features)]
#![allow(type_alias_bounds)]
// As dst-tuple.rs, but the unsized field is the only field in the tuple.
#![feature(unsized_tuple_coercion)]
type Fat<T: ?Sized> = (T,);
// x is a fat pointer
fn foo(x: &Fat<[isize]>) {
let y = &x.0;
assert_eq!(x.0.len(), 3);
assert_eq!(y[0], 1);
assert_eq!(x.0[1], 2);
}
fn foo2<T:ToBar>(x: &Fat<[T]>) {
let y = &x.0;
let bar = Bar;
assert_eq!(x.0.len(), 3);
assert_eq!(y[0].to_bar(), bar);
assert_eq!(x.0[1].to_bar(), bar);
}
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
struct Bar;
trait ToBar {
fn to_bar(&self) -> Bar;
}
impl ToBar for Bar {
fn to_bar(&self) -> Bar {
*self
}
}
pub fn main() {
// With a vec of ints.
let f1 = ([1, 2, 3],);
foo(&f1);
let f2 = &f1;
foo(f2);
let f3: &Fat<[isize]> = f2;
foo(f3);
let f4: &Fat<[isize]> = &f1;
foo(f4);
let f5: &Fat<[isize]> = &([1, 2, 3],);
foo(f5);
// With a vec of Bars.
let bar = Bar;
let f1 = ([bar, bar, bar],);
foo2(&f1);
let f2 = &f1;
foo2(f2);
let f3: &Fat<[Bar]> = f2;
foo2(f3);
let f4: &Fat<[Bar]> = &f1;
foo2(f4);
let f5: &Fat<[Bar]> = &([bar, bar, bar],);
foo2(f5);
// Assignment.
let f5: &mut Fat<[isize]> = &mut ([1, 2, 3],);
f5.0[1] = 34;
assert_eq!(f5.0[0], 1);
assert_eq!(f5.0[1], 34);
assert_eq!(f5.0[2], 3);
// Zero size vec.
let f5: &Fat<[isize]> = &([],);
assert!(f5.0.is_empty());
let f5: &Fat<[Bar]> = &([],);
assert!(f5.0.is_empty());
}
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