// run-pass // check raw fat pointer ops use std::mem; fn assert_inorder(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; } impl Foo for T { fn foo(&self) -> usize { mem::size_of::() } } #[allow(unused_tuple_struct_fields)] struct S(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]> ]); }