Question

I’m implementing an output stream operator<< overload, and I need to check that the output stream parameter os is std::cout, and if not, throw std::runtime_error – how can I check it?

   friend std::ostream& operator<<(std::ostream& os, const Software &soft)

Answer 1

I question the kind of logic that would lead you to think you have to do this, but if you really want to…

if (&os != &std::cout) {
    throw std::runtime_error(/* ... */);
}