C++ High Performance

Pointer-mimicking syntax

Now that we covered the basics of iterators, let's see how C++ implements it syntactically. As mentioned above, the syntax of C++ iterators are implemented in terms of standard C pointer notation. This means that any algorithm built upon iterators will also work with regular C pointers.

The step functions are implemented using pointer arithmetic. The following table shows which operator is overloaded for each step function, and how to invoke the function on an imagined iterator object called it:

Denoted function	Overloaded operator	Usage example
step_fwd() -> void;	operator++()	++it;
step_bwd() -> void;	operator--()	--it;
step(int n) -> void;	operator+=(int n)	it += 5;

The read() and write() functions ...