mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-04 20:54:13 +00:00
40 lines
1001 B
Rust
40 lines
1001 B
Rust
#![allow(dead_code)]
|
|
|
|
fn main() {}
|
|
|
|
#[allow(unnecessary_operation)]
|
|
fn starts_with() {
|
|
"".chars().next() == Some(' ');
|
|
Some(' ') != "".chars().next();
|
|
}
|
|
|
|
fn chars_cmp_with_unwrap() {
|
|
let s = String::from("foo");
|
|
if s.chars().next().unwrap() == 'f' { // s.starts_with('f')
|
|
// Nothing here
|
|
}
|
|
if s.chars().next_back().unwrap() == 'o' { // s.ends_with('o')
|
|
// Nothing here
|
|
}
|
|
if s.chars().last().unwrap() == 'o' { // s.ends_with('o')
|
|
// Nothing here
|
|
}
|
|
if s.chars().next().unwrap() != 'f' { // !s.starts_with('f')
|
|
// Nothing here
|
|
}
|
|
if s.chars().next_back().unwrap() != 'o' { // !s.ends_with('o')
|
|
// Nothing here
|
|
}
|
|
if s.chars().last().unwrap() != 'o' { // !s.ends_with('o')
|
|
// Nothing here
|
|
}
|
|
}
|
|
|
|
#[allow(unnecessary_operation)]
|
|
fn ends_with() {
|
|
"".chars().last() == Some(' ');
|
|
Some(' ') != "".chars().last();
|
|
"".chars().next_back() == Some(' ');
|
|
Some(' ') != "".chars().next_back();
|
|
}
|