Method cend

rx/include/rx/StaticString.hpp:103–105

  [[nodiscard]] constexpr char *end() noexcept { return m_data + m_size; }
  [[nodiscard]] constexpr const char *cbegin() const noexcept { return m_data; }
  [[nodiscard]] constexpr const char *cend() const noexcept {
    return m_data + m_size;
  }

  constexpr char &operator[](std::size_t pos) noexcept { return m_data[pos]; }