Merge pull request #3650 from avsaase/either-is

Add is_x() methods for all EitherN enum variants

embassy-futures/src/select.rs

@@ -14,6 +14,18 @@ pub enum Either<A, B> {
     Second(B),
 }
 
+impl<A, B> Either<A, B> {
+    /// Did the first future complete first?
+    pub fn is_first(&self) -> bool {
+        matches!(self, Either::First(_))
+    }
+
+    /// Did the second future complete first?
+    pub fn is_second(&self) -> bool {
+        matches!(self, Either::Second(_))
+    }
+}
+
 /// Wait for one of two futures to complete.
 ///
 /// This function returns a new future which polls all the futures.
@@ -73,6 +85,23 @@ pub enum Either3<A, B, C> {
     Third(C),
 }
 
+impl<A, B, C> Either3<A, B, C> {
+    /// Did the first future complete first?
+    pub fn is_first(&self) -> bool {
+        matches!(self, Either3::First(_))
+    }
+
+    /// Did the second future complete first?
+    pub fn is_second(&self) -> bool {
+        matches!(self, Either3::Second(_))
+    }
+
+    /// Did the third future complete first?
+    pub fn is_third(&self) -> bool {
+        matches!(self, Either3::Third(_))
+    }
+}
+
 /// Same as [`select`], but with more futures.
 pub fn select3<A, B, C>(a: A, b: B, c: C) -> Select3<A, B, C>
 where
@@ -134,6 +163,28 @@ pub enum Either4<A, B, C, D> {
     Fourth(D),
 }
 
+impl<A, B, C, D> Either4<A, B, C, D> {
+    /// Did the first future complete first?
+    pub fn is_first(&self) -> bool {
+        matches!(self, Either4::First(_))
+    }
+
+    /// Did the second future complete first?
+    pub fn is_second(&self) -> bool {
+        matches!(self, Either4::Second(_))
+    }
+
+    /// Did the third future complete first?
+    pub fn is_third(&self) -> bool {
+        matches!(self, Either4::Third(_))
+    }
+
+    /// Did the fourth future complete first?
+    pub fn is_fourth(&self) -> bool {
+        matches!(self, Either4::Fourth(_))
+    }
+}
+
 /// Same as [`select`], but with more futures.
 pub fn select4<A, B, C, D>(a: A, b: B, c: C, d: D) -> Select4<A, B, C, D>
 where
@@ -204,6 +255,33 @@ pub enum Either5<A, B, C, D, E> {
     Fifth(E),
 }
 
+impl<A, B, C, D, E> Either5<A, B, C, D, E> {
+    /// Did the first future complete first?
+    pub fn is_first(&self) -> bool {
+        matches!(self, Either5::First(_))
+    }
+
+    /// Did the second future complete first?
+    pub fn is_second(&self) -> bool {
+        matches!(self, Either5::Second(_))
+    }
+
+    /// Did the third future complete first?
+    pub fn is_third(&self) -> bool {
+        matches!(self, Either5::Third(_))
+    }
+
+    /// Did the fourth future complete first?
+    pub fn is_fourth(&self) -> bool {
+        matches!(self, Either5::Fourth(_))
+    }
+
+    /// Did the fifth future complete first?
+    pub fn is_fifth(&self) -> bool {
+        matches!(self, Either5::Fifth(_))
+    }
+}
+
 /// Same as [`select`], but with more futures.
 pub fn select5<A, B, C, D, E>(a: A, b: B, c: C, d: D, e: E) -> Select5<A, B, C, D, E>
 where
@@ -283,6 +361,38 @@ pub enum Either6<A, B, C, D, E, F> {
     Sixth(F),
 }
 
+impl<A, B, C, D, E, F> Either6<A, B, C, D, E, F> {
+    /// Did the first future complete first?
+    pub fn is_first(&self) -> bool {
+        matches!(self, Either6::First(_))
+    }
+
+    /// Did the second future complete first?
+    pub fn is_second(&self) -> bool {
+        matches!(self, Either6::Second(_))
+    }
+
+    /// Did the third future complete first?
+    pub fn is_third(&self) -> bool {
+        matches!(self, Either6::Third(_))
+    }
+
+    /// Did the fourth future complete first?
+    pub fn is_fourth(&self) -> bool {
+        matches!(self, Either6::Fourth(_))
+    }
+
+    /// Did the fifth future complete first?
+    pub fn is_fifth(&self) -> bool {
+        matches!(self, Either6::Fifth(_))
+    }
+
+    /// Did the sixth future complete first?
+    pub fn is_sixth(&self) -> bool {
+        matches!(self, Either6::Sixth(_))
+    }
+}
+
 /// Same as [`select`], but with more futures.
 pub fn select6<A, B, C, D, E, F>(a: A, b: B, c: C, d: D, e: E, f: F) -> Select6<A, B, C, D, E, F>
 where