Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs
new file mode 100644
index 000000000..f7a8aa0d9
--- /dev/null
+++ b/library/core/src/bool.rs
@@ -0,0 +1,44 @@
+//! impl bool {}
+
+use crate::marker::Destruct;
+
+impl bool {
+    /// Returns `Some(t)` if the `bool` is [`true`](../std/keyword.true.html),
+    /// or `None` otherwise.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// assert_eq!(false.then_some(0), None);
+    /// assert_eq!(true.then_some(0), Some(0));
+    /// ```
+    #[stable(feature = "bool_to_option", since = "1.62.0")]
+    #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
+    #[inline]
+    pub const fn then_some<T>(self, t: T) -> Option<T>
+    where
+        T: ~const Destruct,
+    {
+        if self { Some(t) } else { None }
+    }
+
+    /// Returns `Some(f())` if the `bool` is [`true`](../std/keyword.true.html),
+    /// or `None` otherwise.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// assert_eq!(false.then(|| 0), None);
+    /// assert_eq!(true.then(|| 0), Some(0));
+    /// ```
+    #[stable(feature = "lazy_bool_to_option", since = "1.50.0")]
+    #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
+    #[inline]
+    pub const fn then<T, F>(self, f: F) -> Option<T>
+    where
+        F: ~const FnOnce() -> T,
+        F: ~const Destruct,
+    {
+        if self { Some(f()) } else { None }
+    }
+}