Method operator[]

include/magic_enum/magic_enum_containers.hpp:369–372

  }

  [[nodiscard]] constexpr reference operator[](E pos) {
    auto i = index_type::at(pos);
    return MAGIC_ENUM_ASSERT(i), a[*i];
  }

  [[nodiscard]] constexpr const_reference operator[](E pos) const {
    auto i = index_type::at(pos);