From 9e538c6d38b9d98b1bd1092f2ced66a269f5ce32 Mon Sep 17 00:00:00 2001
From: barryz <barryzxb@gmail.com>
Date: Tue, 23 Jul 2019 23:43:19 +0800
Subject: [PATCH] implments Toggle method more explicit and simple.

---
 README.md    |  2 +-
 bool.go      |  6 +++---
 bool_test.go | 13 +++++++++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 627883d..810b1ae 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ cond.IsSet()               // Returns true
 cond.UnSet()               // Set to false
 cond.SetTo(true)           // Set to whatever you want
 cond.SetToIf(false, true)  // Set to true if it is false, returns false(not set)
-cond.Toggle() bool         // Toggle the boolean value atomically and returns the previous value.
+cond.Toggle() *AtomicBool  // Negates boolean atomically and returns a new AtomicBool object which holds previous boolean value.
 
 
 // embedding
diff --git a/bool.go b/bool.go
index 401c11f..3a3ca64 100644
--- a/bool.go
+++ b/bool.go
@@ -49,9 +49,9 @@ func (ab *AtomicBool) SetTo(yes bool) {
 	}
 }
 
-// Toggle negates boolean atomically and returns the previous value.
-func (ab *AtomicBool) Toggle() bool {
-	return (atomic.AddInt32((*int32)(ab), 1)-1)&1 == 1
+// Toggle negates boolean atomically and returns a new AtomicBool object which holds previous boolean value.
+func (ab *AtomicBool) Toggle() *AtomicBool {
+	return NewBool(atomic.AddInt32((*int32)(ab), 1)&1 == 0)
 }
 
 // SetToIf sets the Boolean to new only if the Boolean matches the old
diff --git a/bool_test.go b/bool_test.go
index 2e9b4f0..18760b0 100644
--- a/bool_test.go
+++ b/bool_test.go
@@ -50,11 +50,20 @@ func TestBool(t *testing.T) {
 		t.Fatal("AtomicBool.SetTo(false, true) failed")
 	}
 
-	_ = v.Toggle() // expected false
+	v = New()
 	if v.IsSet() {
-		t.Fatal("AtomicBool.Toggle() failed")
+		t.Fatal("Empty value of AtomicBool should be false")
+	}
+
+	_ = v.Toggle()
+	if !v.IsSet() {
+		t.Fatal("AtomicBool.Toggle() to true failed")
 	}
 
+	prev := v.Toggle()
+	if v.IsSet() == prev.IsSet() {
+		t.Fatal("AtomicBool.Toggle() to false failed")
+	}
 }
 
 func TestRace(t *testing.T) {