1 //! impl bool {}
2 
3 #[lang = "bool"]
4 impl bool {
5     /// Returns `Some(t)` if the `bool` is [`true`](../std/keyword.true.html),
6     /// or `None` otherwise.
7     ///
8     /// # Examples
9     ///
10     /// ```
11     /// #![feature(bool_to_option)]
12     ///
13     /// assert_eq!(false.then_some(0), None);
14     /// assert_eq!(true.then_some(0), Some(0));
15     /// ```
16     #[unstable(feature = "bool_to_option", issue = "80967")]
17     #[inline]
then_some<T>(self, t: T) -> Option<T>18     pub fn then_some<T>(self, t: T) -> Option<T> {
19         if self { Some(t) } else { None }
20     }
21 
22     /// Returns `Some(f())` if the `bool` is [`true`](../std/keyword.true.html),
23     /// or `None` otherwise.
24     ///
25     /// # Examples
26     ///
27     /// ```
28     /// assert_eq!(false.then(|| 0), None);
29     /// assert_eq!(true.then(|| 0), Some(0));
30     /// ```
31     #[stable(feature = "lazy_bool_to_option", since = "1.50.0")]
32     #[inline]
then<T, F: FnOnce() -> T>(self, f: F) -> Option<T>33     pub fn then<T, F: FnOnce() -> T>(self, f: F) -> Option<T> {
34         if self { Some(f()) } else { None }
35     }
36 }
37