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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// As dst-struct.rs, but the unsized field is the only field in the struct.
struct Fat<T: ?Sized> {
ptr: T
}
// x is a fat pointer
fn foo(x: &Fat<[isize]>) {
let y = &x.ptr;
assert_eq!(x.ptr.len(), 3);
assert_eq!(y[0], 1);
assert_eq!(x.ptr[1], 2);
}
fn foo2<T:ToBar>(x: &Fat<[T]>) {
let y = &x.ptr;
let bar = Bar;
assert_eq!(x.ptr.len(), 3);
assert_eq!(y[0].to_bar(), bar);
assert_eq!(x.ptr[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 = Fat { ptr: [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]> = &Fat { ptr: [1, 2, 3] };
foo(f5);
// With a vec of Bars.
let bar = Bar;
let f1 = Fat { ptr: [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]> = &Fat { ptr: [bar, bar, bar] };
foo2(f5);
// Assignment.
let f5: &mut Fat<[isize]> = &mut Fat { ptr: [1, 2, 3] };
f5.ptr[1] = 34;
assert_eq!(f5.ptr[0], 1);
assert_eq!(f5.ptr[1], 34);
assert_eq!(f5.ptr[2], 3);
// Zero size vec.
let f5: &Fat<[isize]> = &Fat { ptr: [] };
assert!(f5.ptr.is_empty());
let f5: &Fat<[Bar]> = &Fat { ptr: [] };
assert!(f5.ptr.is_empty());
}
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