message: Add missing return value on assignment operator
diff: @@ -45,5 +45,9 @@ public:
  }
  inline bool operator==(const BitFlagIterator &rhs) const { return flags == rhs.flags; }
  inline bool operator!=(const BitFlagIterator &rhs) const { return flags != rhs.flags; }
  - inline BitFlagIterator &operator=(const BitFlagIterator &rhs) { flags = rhs.flags; }
  + inline BitFlagIterator &operator=(const BitFlagIterator &rhs)
  + {
  + flags = rhs.flags;
  + return *this;
  + }
  };
  