Help stream operator overloading in c++?

actuall i want to ask why do we call by refrence and then return it in the following . i mean the changes must hav been reflected.





ostream%26amp; operator %26lt;%26lt;(ostream %26amp;os,const Base %26amp;obj)


{


os%26lt;%26lt;obj.strVal;


return os;


}

Help stream operator overloading in c++?
At the time of the return, the changes *have* been reflected in the stream "os".





Returning the non-const reference to the stream facilitates chaining of the "%26lt;%26lt;" operator. The most prevalent use of such chaining is when using cout.