Where are "this" pointers are assigned ?

[Lacura]

As we all know, in C++, this means a pointer to
the object itself. But where and when is the pointer
created?

I have try the follwing cod:

class A{
A(){ cout<<"A::A() is called."; }
A(int a){ A(); cout<<"A:A(int a) is called"; };
~A(){ cout<<"A is destructing ...";}
}

main(){
A a;
return 0;
}

it shows that in the constructor A::A(int),
another tempory object of A is created.
Then the question is rasied:
Where and when is this be assigned,
at the beginning or at the end of the constructor?