Rumal a header only HTML/CSS/Javascript Generator C++ library

Rumal is a C++ library that can generate HTML/CSS/Javascript code from significantly identical C++ syntax.
Currently it uses std::string which is supposed to be replaced with compile time strings. Injecting placeholders, is also planned but not yet implemented.
This will make it usable as a template engine.

std::cout << 
    div(_id(42) / _class("test"),
        span(_id(43) / _class("test"), "Hello"),
        span("World")
    );