ptr: add NonDefault

ptr/ptr.go

@@ -6,6 +6,7 @@
 
 package ptr
 
+// Clone creates a shallow copy of the given pointer.
 func Clone[T any](val *T) *T {
 	if val == nil {
 		return nil
@@ -14,18 +15,26 @@ func Clone[T any](val *T) *T {
 	return &valCopy
 }
 
+// Ptr returns a pointer to the given value.
 func Ptr[T any](val T) *T {
 	return &val
 }
 
+// NonZero returns a pointer to the given comparable value, unless the value is the type's zero value.
 func NonZero[T comparable](val T) *T {
 	var zero T
-	if val == zero {
+	return NonDefault(val, zero)
+}
+
+// NonDefault returns a pointer to the first parameter, unless it is equal to the second parameter.
+func NonDefault[T comparable](val, def T) *T {
+	if val == def {
 		return nil
 	}
 	return &val
 }
 
+// Val returns the value of the given pointer, or the zero value of the type if the pointer is nil.
 func Val[T any](ptr *T) (val T) {
 	if ptr != nil {
 		val = *ptr