1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Test the trivial_casts and trivial_numeric_casts lints. For each error we also
12 // check that the cast can be done using just coercion.
14 #![deny(trivial_casts, trivial_numeric_casts)]
26 let _ = 42_i32 as i32; //~ ERROR trivial numeric cast: `i32` as `i32`
29 let _ = 42_u8 as u8; //~ ERROR trivial numeric cast: `u8` as `u8`
34 let _ = x as *const u32; //~ERROR trivial cast: `&u32` as `*const u32`
35 let _: *const u32 = x;
37 let x: &mut u32 = &mut 42;
38 let _ = x as *mut u32; //~ERROR trivial cast: `&mut u32` as `*mut u32`
42 let x: &[u32; 3] = &[42, 43, 44];
43 let _ = x as &[u32]; //~ERROR trivial cast: `&[u32; 3]` as `&[u32]`
44 let _ = x as *const [u32]; //~ERROR trivial cast: `&[u32; 3]` as `*const [u32]`
46 let _: *const [u32] = x;
48 let x: &mut [u32; 3] = &mut [42, 43, 44];
49 let _ = x as &mut [u32]; //~ERROR trivial cast: `&mut [u32; 3]` as `&mut [u32]`
50 let _ = x as *mut [u32]; //~ERROR trivial cast: `&mut [u32; 3]` as `*mut [u32]`
51 let _: &mut [u32] = x;
52 let _: *mut [u32] = x;
54 let x: Box<[u32; 3]> = Box::new([42, 43, 44]);
55 let _ = x as Box<[u32]>;
56 //~^ ERROR trivial cast: `std::boxed::Box<[u32; 3]>` as `std::boxed::Box<[u32]>`
57 let x: Box<[u32; 3]> = Box::new([42, 43, 44]);
58 let _: Box<[u32]> = x;
62 let _ = x as &Foo; //~ERROR trivial cast: `&Bar` as `&dyn Foo`
63 let _ = x as *const Foo; //~ERROR trivial cast: `&Bar` as `*const dyn Foo`
65 let _: *const Foo = x;
67 let x: &mut Bar = &mut Bar;
68 let _ = x as &mut Foo; //~ERROR trivial cast: `&mut Bar` as `&mut dyn Foo`
69 let _ = x as *mut Foo; //~ERROR trivial cast: `&mut Bar` as `*mut dyn Foo`
73 let x: Box<Bar> = Box::new(Bar);
74 let _ = x as Box<Foo>; //~ERROR `std::boxed::Box<Bar>` as `std::boxed::Box<dyn Foo>`
75 let x: Box<Bar> = Box::new(Bar);
80 let _ = &baz as &Fn(i32); //~ERROR `&fn(i32) {main::baz}` as `&dyn std::ops::Fn(i32)`
81 let _: &Fn(i32) = &baz;
83 let _ = &x as &Fn(i32); //~ERROR trivial cast
88 pub fn test_subtyping<'a, 'b: 'a>(a: &'a Bar, b: &'b Bar) {
89 let _ = a as &'a Bar; //~ERROR trivial cast
91 let _ = b as &'a Bar; //~ERROR trivial cast
93 let _ = b as &'b Bar; //~ERROR trivial cast