Function as

include/tabulate/optional_lite.hpp:733–733

  optional_nodiscard void const *ptr() const optional_noexcept { return &data; }

  template <typename U> optional_nodiscard U *as() { return reinterpret_cast<U *>(ptr()); }

  template <typename U> optional_nodiscard U const *as() const {
    return reinterpret_cast<U const *>(ptr());