ostream chaining, output order

Question

I have a function that takes an ostream reference as an argument, writes some data to the stream, and then returns a reference to that same stream, like so:

Answer 1

The reason is that your print() function will be evaluated before the rest of the statement and return a reference to cout which is then actually printed as a pointer (cout << cout). This order of evaluation is actually unspecified behavior, but seems to be the case with your compiler.

As for defining a stream aware "function" that actually has defined behavior with the same functionality, this would work;

#include 

template 
  std::basic_ostream& print ( std::basic_ostream& os )
{
        os << " How are you?" << std::endl;
        return os;
}

int main() {
  std::cout << "Hello, world!" << print << std::endl;
}

See also this answer for a little more detail on what "unspecified" actually means in this case.