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c++overloadingthisoperator-keyword

Overloading Ostream operator

I found that when i create ostream operator within a class or a struct it only accepts one parameter as the second is This pointer so i tried to do it this way and it is not working though

P.S I know that i should create it outside the class or the struct as a free function But I am trying to understand why ?

struct Vector2 
{
    float x,y ; 
    Vector2(float ax , float ay )
    {
        x = ax ; 
        y = ay ; 
    }
    std:: ostream&  operator<< (std::ostream&  stream )
    { 
        return stream <<this->x<< " , "<< this->y ; 
    }
}
Solution

  • When << is overloaded, a << b means either

    operator<<(a,b)

    if the overload is a free function, or

    a.operator<<(b)

    if it is a member.

    That is, for an operator defined as a member, the left-hand argument is *this, and you need to write

    Vector2 v;
v << std::cout;

    wihch is equivalent to

    Vector2 v;
v.operator<<(std::cout);