| // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Test the trivial_casts and trivial_numeric_casts lints. For each error we also |
| // check that the cast can be done using just coercion. |
| |
| #![deny(trivial_casts, trivial_numeric_casts)] |
| |
| trait Foo { |
| fn foo(&self) {} |
| } |
| |
| pub struct Bar; |
| |
| impl Foo for Bar {} |
| |
| pub fn main() { |
| // Numeric |
| let _ = 42_i32 as i32; //~ ERROR trivial numeric cast: `i32` as `i32` |
| let _: i32 = 42_i32; |
| |
| let _ = 42_u8 as u8; //~ ERROR trivial numeric cast: `u8` as `u8` |
| let _: u8 = 42_u8; |
| |
| // & to * pointers |
| let x: &u32 = &42; |
| let _ = x as *const u32; //~ERROR trivial cast: `&u32` as `*const u32` |
| let _: *const u32 = x; |
| |
| let x: &mut u32 = &mut 42; |
| let _ = x as *mut u32; //~ERROR trivial cast: `&mut u32` as `*mut u32` |
| let _: *mut u32 = x; |
| |
| // unsize array |
| let x: &[u32; 3] = &[42, 43, 44]; |
| let _ = x as &[u32]; //~ERROR trivial cast: `&[u32; 3]` as `&[u32]` |
| let _ = x as *const [u32]; //~ERROR trivial cast: `&[u32; 3]` as `*const [u32]` |
| let _: &[u32] = x; |
| let _: *const [u32] = x; |
| |
| let x: &mut [u32; 3] = &mut [42, 43, 44]; |
| let _ = x as &mut [u32]; //~ERROR trivial cast: `&mut [u32; 3]` as `&mut [u32]` |
| let _ = x as *mut [u32]; //~ERROR trivial cast: `&mut [u32; 3]` as `*mut [u32]` |
| let _: &mut [u32] = x; |
| let _: *mut [u32] = x; |
| |
| let x: Box<[u32; 3]> = Box::new([42, 43, 44]); |
| let _ = x as Box<[u32]>; |
| //~^ ERROR trivial cast: `std::boxed::Box<[u32; 3]>` as `std::boxed::Box<[u32]>` |
| let x: Box<[u32; 3]> = Box::new([42, 43, 44]); |
| let _: Box<[u32]> = x; |
| |
| // unsize trait |
| let x: &Bar = &Bar; |
| let _ = x as &Foo; //~ERROR trivial cast: `&Bar` as `&dyn Foo` |
| let _ = x as *const Foo; //~ERROR trivial cast: `&Bar` as `*const dyn Foo` |
| let _: &Foo = x; |
| let _: *const Foo = x; |
| |
| let x: &mut Bar = &mut Bar; |
| let _ = x as &mut Foo; //~ERROR trivial cast: `&mut Bar` as `&mut dyn Foo` |
| let _ = x as *mut Foo; //~ERROR trivial cast: `&mut Bar` as `*mut dyn Foo` |
| let _: &mut Foo = x; |
| let _: *mut Foo = x; |
| |
| let x: Box<Bar> = Box::new(Bar); |
| let _ = x as Box<Foo>; //~ERROR `std::boxed::Box<Bar>` as `std::boxed::Box<dyn Foo>` |
| let x: Box<Bar> = Box::new(Bar); |
| let _: Box<Foo> = x; |
| |
| // functions |
| fn baz(_x: i32) {} |
| let _ = &baz as &Fn(i32); //~ERROR `&fn(i32) {main::baz}` as `&dyn std::ops::Fn(i32)` |
| let _: &Fn(i32) = &baz; |
| let x = |_x: i32| {}; |
| let _ = &x as &Fn(i32); //~ERROR trivial cast |
| let _: &Fn(i32) = &x; |
| } |
| |
| // subtyping |
| pub fn test_subtyping<'a, 'b: 'a>(a: &'a Bar, b: &'b Bar) { |
| let _ = a as &'a Bar; //~ERROR trivial cast |
| let _: &'a Bar = a; |
| let _ = b as &'a Bar; //~ERROR trivial cast |
| let _: &'a Bar = b; |
| let _ = b as &'b Bar; //~ERROR trivial cast |
| let _: &'b Bar = b; |
| } |