Method begin

include/boost/histogram/axis/base.hpp:117–119

  using const_reverse_iterator = reverse_iterator_over<Derived>;

  const_iterator begin() const noexcept {
    return const_iterator(*static_cast<const Derived*>(this), 0);
  }
  const_iterator end() const noexcept {
    return const_iterator(*static_cast<const Derived*>(this),
                          static_cast<const Derived*>(this)->size());