C++ Primer Plus

Pointers and Numbers

Pointers are not integer types, even though computers typically handle addresses as integers. Conceptually, pointers are distinct types from integers. Integers are numbers you can add, subtract, divide, and so on. But a pointer describes a location, and it doesn’t make sense, for example, to multiply two locations by each other. In terms of the operations you can perform with them, pointers and integers are different from each other. Consequently, you can’t simply assign an integer to a pointer:

int * pt;pt = 0xB8000000;  // type mismatch

Here, the left side is a pointer to int, so you can assign it an address, but the right side is just an integer. You might know that 0xB8000000 is the combined segment-offset address of ...