WriteIntoWriter handles error values

chan_io.go

@@ -23,6 +23,10 @@ func WriteIntoDelayed[T any](ch chan<- T, delay time.Duration, values ...T) {
 func WriteIntoWriter[T any](ch <-chan T, writers ...io.Writer) {
 	w := io.MultiWriter(writers...)
 	EachSuccessive(ch, func(value T) {
+		if err, ok := any(value).(error); ok {
+			fmt.Fprintln(w, err.Error())
+			return
+		}
 		fmt.Fprintln(w, value)
 	})
 }