9.1 Introduction to operator ove

原完整教程链接：Introduction to operator overloading

In C++, operators are implemented as functions.

1. If any of the operands are user data types (e.g. one of your classes, or an enum type), the compiler looks to see whether the type has a matching overloaded operator function that it can call. If it can’t find one, it will try to convert one or more of the user-defined type operands into fundamental data types.

2. Almost any existing operator in C++ can be overloaded. The exceptions are: conditional (?:), sizeof, scope (::), member selector (.), and member pointer selector (.*).

3. You can only overload the operators that exist. You can not create new operators or rename existing operators. For example, you could not create an operator ** to do exponents.