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| 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. |
| 4 | +// |
| 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. |
| 10 | + |
| 11 | +// Test the trivial_cast and trivial_numeric_cast lints. For each error we also |
| 12 | +// check that the cast can be done using just coercion. |
| 13 | + |
| 14 | +#![deny(trivial_cast, trivial_numeric_cast)] |
| 15 | + |
| 16 | +trait Foo { |
| 17 | + fn foo(&self) {} |
| 18 | +} |
| 19 | + |
| 20 | +pub struct Bar; |
| 21 | + |
| 22 | +impl Foo for Bar {} |
| 23 | + |
| 24 | +pub fn main() { |
| 25 | + // Numeric |
| 26 | + let _ = 42_i32 as i32; //~ ERROR trivial numeric cast: `i32` as `i32` |
| 27 | + let _: i32 = 42_i32; |
| 28 | + |
| 29 | + let _ = 42_u8 as u8; //~ ERROR trivial numeric cast: `u8` as `u8` |
| 30 | + let _: u8 = 42_u8; |
| 31 | + |
| 32 | + // & to * pointers |
| 33 | + let x: &u32 = &42; |
| 34 | + let _ = x as *const u32; //~ERROR trivial cast: `&u32` as `*const u32` |
| 35 | + let _: *const u32 = x; |
| 36 | + |
| 37 | + let x: &mut u32 = &mut 42; |
| 38 | + let _ = x as *mut u32; //~ERROR trivial cast: `&mut u32` as `*mut u32` |
| 39 | + let _: *mut u32 = x; |
| 40 | + |
| 41 | + // unsize array |
| 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]` |
| 45 | + let _: &[u32] = x; |
| 46 | + let _: *const [u32] = x; |
| 47 | + |
| 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; |
| 53 | + |
| 54 | + let x: Box<[u32; 3]> = Box::new([42, 43, 44]); |
| 55 | + let _ = x as Box<[u32]>; //~ERROR trivial cast: `Box<[u32; 3]>` as `Box<[u32]>` |
| 56 | + let x: Box<[u32; 3]> = Box::new([42, 43, 44]); |
| 57 | + let _: Box<[u32]> = x; |
| 58 | + |
| 59 | + // unsize trait |
| 60 | + let x: &Bar = &Bar; |
| 61 | + let _ = x as &Foo; //~ERROR trivial cast: `&Bar` as `&Foo` |
| 62 | + let _ = x as *const Foo; //~ERROR trivial cast: `&Bar` as `*const Foo` |
| 63 | + let _: &Foo = x; |
| 64 | + let _: *const Foo = x; |
| 65 | + |
| 66 | + let x: &mut Bar = &mut Bar; |
| 67 | + let _ = x as &mut Foo; //~ERROR trivial cast: `&mut Bar` as `&mut Foo` |
| 68 | + let _ = x as *mut Foo; //~ERROR trivial cast: `&mut Bar` as `*mut Foo` |
| 69 | + let _: &mut Foo = x; |
| 70 | + let _: *mut Foo = x; |
| 71 | + |
| 72 | + let x: Box<Bar> = Box::new(Bar); |
| 73 | + let _ = x as Box<Foo>; //~ERROR trivial cast: `Box<Bar>` as `Box<Foo>` |
| 74 | + let x: Box<Bar> = Box::new(Bar); |
| 75 | + let _: Box<Foo> = x; |
| 76 | + |
| 77 | + // functions |
| 78 | + fn baz(_x: i32) {} |
| 79 | + let _ = &baz as &Fn(i32); //~ERROR trivial cast: `&fn(i32) {main::baz}` as `&core::ops::Fn(i32)` |
| 80 | + let _: &Fn(i32) = &baz; |
| 81 | + let x = |_x: i32| {}; |
| 82 | + let _ = &x as &Fn(i32); //~ERROR trivial cast |
| 83 | + let _: &Fn(i32) = &x; |
| 84 | +} |
| 85 | + |
| 86 | +// subtyping |
| 87 | +pub fn test_subtyping<'a, 'b: 'a>(a: &'a Bar, b: &'b Bar) { |
| 88 | + let _ = a as &'a Bar; //~ERROR trivial cast |
| 89 | + let _: &'a Bar = a; |
| 90 | + let _ = b as &'a Bar; //~ERROR trivial cast |
| 91 | + let _: &'a Bar = b; |
| 92 | + let _ = b as &'b Bar; //~ERROR trivial cast |
| 93 | + let _: &'b Bar = b; |
| 94 | +} |
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