1 // run-pass
2 // Test that all coercions can actually be done using casts (modulo the lints).
3
4 #![allow(trivial_casts, trivial_numeric_casts)]
5
6 trait Foo {
foo(&self)7 fn foo(&self) {}
8 }
9
10 pub struct Bar;
11
12 impl Foo for Bar {}
13
main()14 pub fn main() {
15 // Numeric
16 let _ = 42_i32 as i32;
17 let _ = 42_u8 as u8;
18
19 // & to * pointers
20 let x: &u32 = &42;
21 let _ = x as *const u32;
22
23 let x: &mut u32 = &mut 42;
24 let _ = x as *mut u32;
25
26 // unsize array
27 let x: &[u32; 3] = &[42, 43, 44];
28 let _ = x as &[u32];
29 let _ = x as *const [u32];
30
31 let x: &mut [u32; 3] = &mut [42, 43, 44];
32 let _ = x as &mut [u32];
33 let _ = x as *mut [u32];
34
35 let x: Box<[u32; 3]> = Box::new([42, 43, 44]);
36 let _ = x as Box<[u32]>;
37
38 // unsize trait
39 let x: &Bar = &Bar;
40 let _ = x as &dyn Foo;
41 let _ = x as *const dyn Foo;
42
43 let x: &mut Bar = &mut Bar;
44 let _ = x as &mut dyn Foo;
45 let _ = x as *mut dyn Foo;
46
47 let x: Box<Bar> = Box::new(Bar);
48 let _ = x as Box<dyn Foo>;
49
50 // functions
51 fn baz(_x: i32) {}
52 let _ = &baz as &dyn Fn(i32);
53 let x = |_x: i32| {};
54 let _ = &x as &dyn Fn(i32);
55 }
56
57 // subtyping
test_subtyping<'a, 'b: 'a>(a: &'a Bar, b: &'b Bar)58 pub fn test_subtyping<'a, 'b: 'a>(a: &'a Bar, b: &'b Bar) {
59 let _ = a as &'a Bar;
60 let _ = b as &'a Bar;
61 let _ = b as &'b Bar;
62 }
63