Also, I think that iostream is really ugly, why didn't they just extend printf()... (which also has some ugly parts, try e.g. printing an uint16_t or a time_t in a way that won't generate warnings on any architecture... but at least the concept itself is OK)

@vaporeon_ did you know that std::endl not only adds a newline but also inexplicably calls a method on the underlying "output stream instance" representing the console output, meaning that writing std::cout << "Hello world" << std::endl is less performant than writing std::cout << "Hello world" << "\n";?