From 5cc8072b8db09c754b0efc773335c0adf003afea Mon Sep 17 00:00:00 2001
From: Aiden <12055114+aidenwallis@users.noreply.github.com>
Date: Sun, 13 Nov 2022 19:16:39 +0000
Subject: [PATCH] add bitmask.Toggle (#18)

---
 bitmask/bitmask.go      | 8 ++++++++
 bitmask/bitmask_test.go | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/bitmask/bitmask.go b/bitmask/bitmask.go
index 4871909..1cc5ae0 100644
--- a/bitmask/bitmask.go
+++ b/bitmask/bitmask.go
@@ -24,3 +24,11 @@ func Remove[T Bit](sum, bit T) T {
 func Has[T Bit](sum, bit T) bool {
 	return (sum & bit) == bit
 }
+
+// Toggle will either add or remove bit from sum depending on whether it currently exists in the bitmask.
+func Toggle[T Bit](sum, bit T) T {
+	if Has(sum, bit) {
+		return Remove(sum, bit)
+	}
+	return Add(sum, bit)
+}
diff --git a/bitmask/bitmask_test.go b/bitmask/bitmask_test.go
index cacfda4..9bb8a34 100644
--- a/bitmask/bitmask_test.go
+++ b/bitmask/bitmask_test.go
@@ -20,4 +20,7 @@ func TestBits(t *testing.T) {
 	assert.Equal(t, a, bitmask.Remove(a|b, b))
 	assert.True(t, bitmask.Has(a|b, b))
 	assert.False(t, bitmask.Has(a|b, c))
+
+	assert.Equal(t, a|b, bitmask.Toggle(a, b))
+	assert.Equal(t, b, bitmask.Toggle(a|b, a))
 }