map.go

@@ -96,29 +96,24 @@ func (m *Map[K, V]) Values() []V {
 // Do calls f with the underlying primitive map.
 // Be aware that this locks m for write access
 // so Do can be used for reading as well as modifiying m.
+// After f returns, the map will be shallow-copied in order to prevent
+// clueless programmers from storing the map and modifying it afterwards.
+// If you need that little bit of optimization, use DoUnsafe instead
 func (m *Map[K, V]) Do(f func(m map[K]V)) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 	f(m.data)
+
+	nm := map[K]V{}
+	for key, value := range m.data {
+		nm[key] = value
+	}
+	m.data = nm
 }
 
-// DoWithError calls f with the underlying primitive map and returns its error.
+// DoUnsafe behaves like Do but does not create a shallow-copy of m
-// Be aware that this locks m for write access
+func (m *Map[K, V]) DoUnsafe(f func(m map[K]V)) {
-// so Do can be used for reading as well as modifiying m.
-func (m *Map[K, V]) DoWithError(f func(m map[K]V) error) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
-	return f(m.data)
+	f(m.data)
-}
-
-// Clone returns a copy of the underlying map data
-func (m *Map[K, V]) Clone() map[K]V {
-	m.mutex.RLock()
-	defer m.mutex.RUnlock()
-
-	c := map[K]V{}
-	for key, value := range m.data {
-		c[key] = value
-	}
-	return c
 }