ostringstream return value

[CPP freshman]

I am confused:

This works fine:
ostringstream& print(ostringst ream&s){
s<<"abcd";
return s;
}

This produces an error:
ostringstream& print(ostringst ream&s){
return s<<"abcd";
}

[CPP freshman]

Replaced ostringstream with ostream, and it worked.

[weaknessforcats]

operator<< returns an ostream&. Your function returns an ostringstream&. For this to work the compiler needs to convert an ostream& to an ostringstream& and that requires a conversion constructor in the ostream class. There isn't one so you get this error.

However you can write your own operator<< to do what you want. The compiler will call it and that will bypass the need of a conversion constructor:

ostringstream& operator<<(ostringstream& ss,  const char* str)
{
    ss << str;
	return ss;
}

Just make sure this function (or its prototype) appears before your print function.