Question

Is it possible to overload << operator such that this works?

void f (int f)
{
}

int main ()
{
    f << 2;
}

What do I need to study for this to work?

Answer 1

f needs to be an instance of a class with overloaded operator <<, or it must return an object of a type with the overloaded operator (but you’d need to call it f()).

struct F
{
   F& operator << (int x) { return *this; }
};

//...
F f;
f << 2;