src/test/compile-fail/lint-type-limits.rs

   1 // Copyright 2012 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 #![allow(dead_code)]
  12
  13 // compile-flags: -D unused-comparisons
  14 fn main() { }
  15
  16 fn foo() {
  17     let mut i = 100_usize;
  18     while i >= 0 { //~ ERROR comparison is useless due to type limits
  19         i -= 1;
  20     }
  21 }
  22
  23 fn bar() -> i8 {
  24     return 123;
  25 }
  26
  27 fn baz() -> bool {
  28     128 > bar() //~ ERROR comparison is useless due to type limits
  29                 //~^ WARNING literal out of range for i8
  30 }
  31
  32 fn bleh() {
  33     let u = 42u8;
  34     let _ = u > 255; //~ ERROR comparison is useless due to type limits
  35     let _ = 255 < u; //~ ERROR comparison is useless due to type limits
  36     let _ = u < 0; //~ ERROR comparison is useless due to type limits
  37     let _ = 0 > u; //~ ERROR comparison is useless due to type limits
  38     let _ = u <= 255; //~ ERROR comparison is useless due to type limits
  39     let _ = 255 >= u; //~ ERROR comparison is useless due to type limits
  40     let _ = u >= 0; //~ ERROR comparison is useless due to type limits
  41     let _ = 0 <= u; //~ ERROR comparison is useless due to type limits
  42 }
  43
  44 fn qux() {
  45     let mut i = 1i8;
  46     while 200 != i { //~ ERROR comparison is useless due to type limits
  47                      //~^ WARNING literal out of range for i8
  48         i += 1;
  49     }
  50 }
  51
  52 fn quy() {
  53     let i = -23_usize; //~ WARNING negation of unsigned int literal may be unintentional
  54                   //~^ WARNING unused variable
  55 }
  56
  57 fn quz() {
  58     let i = 23_usize;
  59     let j = -i;   //~ WARNING negation of unsigned int variable may be unintentional
  60                   //~^ WARNING unused variable
  61 }