rust/src/test/ui/unsized3-rpass.rs
2019-07-27 18:56:17 +03:00

97 lines
2.0 KiB
Rust

// run-pass
// Test structs with always-unsized fields.
#![allow(warnings)]
#![feature(box_syntax, unsize, raw)]
use std::mem;
use std::raw;
use std::slice;
struct Foo<T> {
f: [T],
}
struct Bar {
f1: usize,
f2: [usize],
}
struct Baz {
f1: usize,
f2: str,
}
trait Tr {
fn foo(&self) -> usize;
}
struct St {
f: usize
}
impl Tr for St {
fn foo(&self) -> usize {
self.f
}
}
struct Qux<'a> {
f: Tr+'a
}
pub fn main() {
let _: &Foo<f64>;
let _: &Bar;
let _: &Baz;
let _: Box<Foo<i32>>;
let _: Box<Bar>;
let _: Box<Baz>;
let _ = mem::size_of::<Box<Foo<u8>>>();
let _ = mem::size_of::<Box<Bar>>();
let _ = mem::size_of::<Box<Baz>>();
unsafe {
struct Foo_<T> {
f: [T; 3]
}
let data: Box<Foo_<i32>> = box Foo_{f: [1, 2, 3] };
let x: &Foo<i32> = mem::transmute(slice::from_raw_parts(&*data, 3));
assert_eq!(x.f.len(), 3);
assert_eq!(x.f[0], 1);
struct Baz_ {
f1: usize,
f2: [u8; 5],
}
let data: Box<_> = box Baz_ {
f1: 42, f2: ['a' as u8, 'b' as u8, 'c' as u8, 'd' as u8, 'e' as u8] };
let x: &Baz = mem::transmute(slice::from_raw_parts(&*data, 5));
assert_eq!(x.f1, 42);
let chs: Vec<char> = x.f2.chars().collect();
assert_eq!(chs.len(), 5);
assert_eq!(chs[0], 'a');
assert_eq!(chs[1], 'b');
assert_eq!(chs[2], 'c');
assert_eq!(chs[3], 'd');
assert_eq!(chs[4], 'e');
struct Qux_ {
f: St
}
let obj: Box<St> = box St { f: 42 };
let obj: &Tr = &*obj;
let obj: raw::TraitObject = mem::transmute(&*obj);
let data: Box<_> = box Qux_{ f: St { f: 234 } };
let x: &Qux = mem::transmute(raw::TraitObject { vtable: obj.vtable,
data: mem::transmute(&*data) });
assert_eq!(x.f.foo(), 234);
}
}