Method reserve

include/stringzilla/stringzilla.hpp:3627–3630

* @brief Informs the string object of a planned change in size, so that it pre-allocate once. * @throw `std::length_error` if the string is too long. */

     *  @throw `std::length_error` if the string is too long.
     */
    void reserve(size_type capacity) noexcept(false) {
        if (capacity > max_size()) throw std::length_error("sz::basic_string::reserve");
        if (!try_reserve(capacity)) throw std::bad_alloc();
    }

    /**
     *  @brief Inserts @b (in-place) a ::character multiple times at the given offset.