I overload a operator for the Communicater class like this:

…
friend bool Communicater::operator << (Communicater c, char a); //重载<<
…
bool operator << (Communicater c, char a){
    …
    return true;
}
…
*communicater << “override test2”;
…

But when I call it, I found that a socket inside the Communicater class unespectingly closed right after the call.

With further debug, I believe its because the WSACleanup() which is in the deconstructor of that class executed and further more close the socket.

I think it’s because using formal parameters Communicater c like this bool operator<<(Communicater c, char *a) will actually bring a copy of the actual parameter， passed with pointer *communicater, which is previously in the heap, into the stack. After calling the function, the copy in the stack deconstructs which clean up all WSA data. ==This is different from Java.==That’s why the socket will be closed unespectingly.

At last, by changing the function into friend bool Communicater::operator << (Communicater &c, char *a); which simply reference the object instead of copying it. Problem solved.

2017/3/15 16:10

Later I found that wrong.

In order to make sure continous operator use works the same, I tried just change it to
friend Communicater Communicater::operator << (Communicater &c, char *a);

and get the same error which that the Communicater &c is still destructed even if it suppose to be working. ==Not sure why.====(Now I get it. It’s still copied…2017/3/15 18:32)==

I tried friend Communicater* Communicater::operator << (Communicater &c, char *a); but this way won’t work either because I need to overwrite for another scenario which is Communicater operator << (Communicater &c, char *a);.

At last, I change it to friend Communicater &Communicater::operator << (Communicater &c, char *a); so that it finally works…

2017/3/15 16:30