T* const this

The hidden *this pointer that's present in every member function of a class (at least, in C++).

class Something
{

int a,b;
public:

Something(int a, int b): this->a(a), this->b(b)

{}

void doSomething() {} // is translated into "void doSomething(Something* const this) {}"

// The T in "T* const this" is replaced with the class type

friend void doSomething2() {} // is not translated, as it is NOT a member function
};
void doSomething2() {}