Overloading the ++ and — Operators in C++
The preincrement, predecrement, postincrement, and postdecrement operators can be overloaded. The ++ and — operators may be prefix or postfix. The prefix ++var or –var first adds or subtracts 1 from the variable and then evaluates to the new value in the var. The postfix var++ or var— adds or subtracts 1 from the variable, [ [ ...]