How to Overload the

Overloading Operator<< to Handle std::endl

When overloading the stream insertion operator (operator<<), a common issue arises when trying to include std::endl as an insertion argument. The error "error C2678: binary '<<' : no operator found" indicates the system's inability to find a compatible operator for the left-hand operand, UIStream.

The underlying reason for this error is that std::endl is not a type, but a function. To overcome this, we must understand how std::cout handles std::endl. std::cout implements operator<< to take a function pointer with the same signature as std::endl. It then calls the function and forwards the return value.

To emulate this behavior, we define an additional operator<< function in our MyStream class that takes a function with the custom MyStreamManipulator signature. This function calls the specified function and returns its return value.

To handle std::endl specifically, we define a static MyStream::endl function that matches the MyStreamManipulator signature. Within this function, we print a new line and perform any additional stream operations, such as flushing the buffer.

Furthermore, we define an operator<< function to accept the StandardEndLine function signature used by std::cout. This function calls the manip function with std::cout as its argument, allowing for the insertion of std::endl.

By following these steps, we can overload operator<< in our custom MyStream class to handle both user-defined data and the insertion of std::endl. This enables us to use MyStream as a versatile alternative to std::cout with full control over stream manipulation.

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