Warning C4430 not being thrown in friend declaration

class myClass;

class otherClass{

public:

otherClass(int x): valor(x){}

inlineint sum(myClass&obj);

private:

int valor;

};

class myClass{

public:

myClass(int x): val(x){}

friend otherClass::sum(myClass&);

private:

int val;

};

inlineint otherClass::sum(myClass&obj){

return obj.val+ valor;

}

The above is a minimalist example to illustrate the problem at hand.

Note how the friend declaration is not defining the return type of otherClass::sum() and yet Warning C4430 is not being thrown.

Is this a bug? Or is there some compiler option I'm setting that precludes the warning?

This is my compiler's command line:

/Od /D "_WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_UNICODE" /D "UNICODE" /FD /EHsc /MDd /Gy /Za /Fo"Debug\\" /Fd"Debug\vc80.pdb" /W4 /nologo /c /Zi /TP /errorReport:prompt

[4564 byte] By [Marfig] at [2007-12-21]