Overloading Arithmetic Operators

Question

The assignment operator can be declared as

T& operator= (const t&);

in a class, but the arithmetic operators cannot be defined that way. It has to be fri

Answer 1

The problem is that if you do something like this:

class A
{
    A& operator+(int n);
    // ...
}

int main()
{
    A my_var;
    int integer = 1;
    A + integer; // compiles
    integer + A // error: no function operator+(int, A) defined
}

it will not compile. A solution is to define operator+(int, A) and operator+(A, int) as friends of A. As a side note, the Boost Operators library makes this process very easy.