2020-04-25 20:33:11 +00:00
|
|
|
#![deny(clippy::bind_instead_of_map)]
|
2022-10-02 19:13:22 +00:00
|
|
|
#![allow(clippy::uninlined_format_args)]
|
2019-08-15 03:53:11 +00:00
|
|
|
|
|
|
|
// need a main anyway, use it get rid of unused warnings too
|
|
|
|
pub fn main() {
|
|
|
|
let x = Some(5);
|
|
|
|
// the easiest cases
|
|
|
|
let _ = x.and_then(Some);
|
|
|
|
let _ = x.and_then(|o| Some(o + 1));
|
|
|
|
// and an easy counter-example
|
|
|
|
let _ = x.and_then(|o| if o < 32 { Some(o) } else { None });
|
|
|
|
|
|
|
|
// Different type
|
|
|
|
let x: Result<u32, &str> = Ok(1);
|
|
|
|
let _ = x.and_then(Ok);
|
|
|
|
}
|
|
|
|
|
|
|
|
pub fn foo() -> Option<String> {
|
|
|
|
let x = Some(String::from("hello"));
|
|
|
|
Some("hello".to_owned()).and_then(|s| Some(format!("{}{}", s, x?)))
|
|
|
|
}
|
2019-08-19 05:41:47 +00:00
|
|
|
|
|
|
|
pub fn example2(x: bool) -> Option<&'static str> {
|
|
|
|
Some("a").and_then(|s| Some(if x { s } else { return None }))
|
|
|
|
}
|