Tutorial Overload Operators

[Selse06]

This Overload Operator function works:

CVector& CVector::operator= (const CVector& param)
{
  x=param.x;
  y=param.y;
  return *this;
}

I tried to use the THIS function also with "opterator-", but it didn't work at all. There are a bit too much indirections included for me I think.

Can anyone explain me, HOW the "bold" things above work / why f.e. the "const" cannot be removed (-> Error).

..and how this must look like, that it works:

CVector& CVector::operator- (const CVector& param){
   x -= param.x;                                             
   y -= param.y;
   return *this;
}

Sorry... but I want to have a good description of this before continuing..

Thanks a lot!

[Lv0f92yv]

CVector& has the ampersand included because you are returning a reference to 'this' (the object itself). The ampersand means 'address of'. You are returning the address of the thing you have just changed.

Same goes for the second example.