From 1993a5f7a866f174aa50329a03b2f8b2f589221c Mon Sep 17 00:00:00 2001
From: benluelo <benluelo@hotmail.com>
Date: Tue, 19 Jul 2022 03:16:07 -0400
Subject: [PATCH] Add map_continue and continue_value combinators to
ControlFlow
Fix type error
Fix continue_value doc comment
---
library/core/src/ops/control_flow.rs | 35 ++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/library/core/src/ops/control_flow.rs b/library/core/src/ops/control_flow.rs
index e34e26746c0a5..b1f5559dcfc17 100644
--- a/library/core/src/ops/control_flow.rs
+++ b/library/core/src/ops/control_flow.rs
@@ -195,6 +195,41 @@ impl<B, C> ControlFlow<B, C> {
ControlFlow::Break(x) => ControlFlow::Break(f(x)),
}
}
+
+ /// Converts the `ControlFlow` into an `Option` which is `Some` if the
+ /// `ControlFlow` was `Continue` and `None` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// #![feature(control_flow_enum)]
+ /// use std::ops::ControlFlow;
+ ///
+ /// assert_eq!(ControlFlow::<i32, String>::Break(3).continue_value(), None);
+ /// assert_eq!(ControlFlow::<String, i32>::Continue(3).continue_value(), Some(3));
+ /// ```
+ #[inline]
+ #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
+ pub fn continue_value(self) -> Option<C> {
+ match self {
+ ControlFlow::Continue(x) => Some(x),
+ ControlFlow::Break(..) => None,
+ }
+ }
+
+ /// Maps `ControlFlow<B, C>` to `ControlFlow<B, T>` by applying a function
+ /// to the continue value in case it exists.
+ #[inline]
+ #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
+ pub fn map_continue<T, F>(self, f: F) -> ControlFlow<B, T>
+ where
+ F: FnOnce(C) -> T,
+ {
+ match self {
+ ControlFlow::Continue(x) => ControlFlow::Continue(f(x)),
+ ControlFlow::Break(x) => ControlFlow::Break(x),
+ }
+ }
}
/// These are used only as part of implementing the iterator adapters.