Compiler Explorer

Source code

#include <boost/core/demangle.hpp>

Newton: type = { }
metre: type = { }

template<class...> struct derived_unit { };
template<class Unit, std::integral Rep> Unit merge(Rep);
template<class Unit1, class Unit2, class Rep> derived_unit<Unit1, Unit2> merge(quantity<Unit2, Rep>);
template<class Unit, class Arg> using merge_units = decltype(merge<Unit>(Arg{}));

template<std::integral Rep> Rep rep(Rep);
template<class Unit, std::integral Rep> Rep rep(quantity<Unit, Rep>);
template<class Rep> using rep_of = decltype(rep(Rep{}));

N: <Rep> type == quantity<Newton, Rep>;
m: <Rep> type == quantity<merge_units<metre, Rep>, Rep>;

quantity: @value <Unit: type, Rep> type
  // requires std::integral<Rep>
= {
  unit: type == Unit;
  rep: type == Rep;
  public value: Rep = ();
  operator=: (out this, val: Rep) = { value = val; }
  // operator=: <Unit2> (out this, q: quantity<Unit2, Rep>) = { value = q.value; }
}

typename_of: (x) -> _ = boost::core::demangle(typeid(x).name());
print: (x) = std::cout << "(typename_of(x))$\n";
main: () = {
  print(N(0));
  print(m(0));
  print(m(N(0)));
}