rust/tests/ui/needless_range_loop.rs

56 lines
1.1 KiB
Rust
Raw Normal View History

2017-10-08 21:37:04 +02:00
fn calc_idx(i: usize) -> usize {
(i + i + 20) % 4
}
fn main() {
let ns = [2, 3, 5, 7];
for i in 3..10 {
println!("{}", ns[i]);
}
for i in 3..10 {
println!("{}", ns[i % 4]);
}
for i in 3..10 {
println!("{}", ns[i % ns.len()]);
}
for i in 3..10 {
println!("{}", ns[calc_idx(i)]);
}
for i in 3..10 {
println!("{}", ns[calc_idx(i) % 4]);
}
let mut ms = vec![1, 2, 3, 4, 5, 6];
for i in 0..ms.len() {
ms[i] *= 2;
}
assert_eq!(ms, vec![2, 4, 6, 8, 10, 12]);
let mut ms = vec![1, 2, 3, 4, 5, 6];
for i in 0..ms.len() {
let x = &mut ms[i];
*x *= 2;
}
assert_eq!(ms, vec![2, 4, 6, 8, 10, 12]);
let g = vec![1, 2, 3, 4, 5, 6];
let glen = g.len();
for i in 0..glen {
let x: u32 = g[i+1..].iter().sum();
println!("{}", g[i] + x);
}
assert_eq!(g, vec![20, 18, 15, 11, 6, 0]);
let mut g = vec![1, 2, 3, 4, 5, 6];
let glen = g.len();
for i in 0..glen {
g[i] = g[i+1..].iter().sum();
}
assert_eq!(g, vec![20, 18, 15, 11, 6, 0]);
2017-10-08 21:37:04 +02:00
}