rust/tests/ui/stdlib-unit-tests/raw-fat-ptr.rs
2024-02-16 20:02:50 +00:00

119 lines
3.2 KiB
Rust

//@ run-pass
// check raw fat pointer ops
use std::mem;
fn assert_inorder<T: PartialEq + PartialOrd>(a: &[T]) {
for i in 0..a.len() {
for j in 0..a.len() {
if i < j {
assert!(a[i] < a[j]);
assert!(a[i] <= a[j]);
assert!(!(a[i] == a[j]));
assert!(a[i] != a[j]);
assert!(!(a[i] >= a[j]));
assert!(!(a[i] > a[j]));
} else if i == j {
assert!(!(a[i] < a[j]));
assert!(a[i] <= a[j]);
assert!(a[i] == a[j]);
assert!(!(a[i] != a[j]));
assert!(a[i] >= a[j]);
assert!(!(a[i] > a[j]));
} else {
assert!(!(a[i] < a[j]));
assert!(!(a[i] <= a[j]));
assert!(!(a[i] == a[j]));
assert!(a[i] != a[j]);
assert!(a[i] >= a[j]);
assert!(a[i] > a[j]);
}
}
}
}
trait Foo { fn foo(&self) -> usize; } //~ WARN method `foo` is never used
impl<T> Foo for T {
fn foo(&self) -> usize {
mem::size_of::<T>()
}
}
#[allow(dead_code)]
struct S<T:?Sized>(u32, T);
fn main() {
let mut array = [0,1,2,3,4];
let mut array2 = [5,6,7,8,9];
// fat ptr comparison: addr then extra
// check ordering for arrays
let mut ptrs: Vec<*const [u8]> = vec![
&array[0..0], &array[0..1], &array, &array[1..]
];
let array_addr = &array as *const [u8] as *const u8 as usize;
let array2_addr = &array2 as *const [u8] as *const u8 as usize;
if array2_addr < array_addr {
ptrs.insert(0, &array2);
} else {
ptrs.push(&array2);
}
assert_inorder(&ptrs);
// check ordering for mut arrays
let mut ptrs: Vec<*mut [u8]> = vec![
&mut array[0..0], &mut array[0..1], &mut array, &mut array[1..]
];
let array_addr = &mut array as *mut [u8] as *mut u8 as usize;
let array2_addr = &mut array2 as *mut [u8] as *mut u8 as usize;
if array2_addr < array_addr {
ptrs.insert(0, &mut array2);
} else {
ptrs.push(&mut array2);
}
assert_inorder(&ptrs);
let mut u8_ = (0u8, 1u8);
let mut u32_ = (4u32, 5u32);
// check ordering for ptrs
let buf: &mut [*const dyn Foo] = &mut [
&u8_, &u8_.0,
&u32_, &u32_.0,
];
buf.sort_by(|u,v| {
let u : [*const (); 2] = unsafe { mem::transmute(*u) };
let v : [*const (); 2] = unsafe { mem::transmute(*v) };
u.cmp(&v)
});
assert_inorder(buf);
// check ordering for mut ptrs
let buf: &mut [*mut dyn Foo] = &mut [
&mut u8_, &mut u8_.0,
&mut u32_, &mut u32_.0,
];
buf.sort_by(|u,v| {
let u : [*const (); 2] = unsafe { mem::transmute(*u) };
let v : [*const (); 2] = unsafe { mem::transmute(*v) };
u.cmp(&v)
});
assert_inorder(buf);
// check ordering for structs containing arrays
let ss: (S<[u8; 2]>,
S<[u8; 3]>,
S<[u8; 2]>) = (
S(7, [8, 9]),
S(10, [11, 12, 13]),
S(4, [5, 6])
);
assert_inorder(&[
&ss.0 as *const S<[u8]>,
&ss.1 as *const S<[u8]>,
&ss.2 as *const S<[u8]>
]);
}