diff --git a/Char.cpp b/Char.cpp
index f29bd0d..a3ef41c 100644
--- a/Char.cpp
+++ b/Char.cpp
@@ -5,6 +5,7 @@
 Char::operator char() const
 { return _string._str->operator[](_index); }
 
+// copy-on-write magic happens here
 Char& Char::operator=(char other)
 {
     auto data = new char[_string.size() + 1];   // space for old string & null-terminator