Daily bit(e) of C++ | std::iostream: custom manipulators
Daily bit(e) of C++ #255, Implementing custom manipulators to adjust formatting/parsing of user defined types.
When implementing stream insertion and extraction, it might be convenient to expose additional options that allow the class users to control how it is formatted or parsed.
Each stream instance comes with an array of options (integers and pointers) that user-defined manipulators can use to store formatting information.