Method capacity

include/stringzilla/stringzilla.hpp:2936–2943

    size_type max_size() const noexcept { return npos - 1; }
    bool empty() const noexcept { return sz_string_length(&string_) == 0; }
    size_type capacity() const noexcept {
        sz_ptr_t string_start;
        sz_size_t string_length;
        sz_size_t string_space;
        sz_bool_t string_is_external;
        sz_string_unpack(&string_, &string_start, &string_length, &string_space, &string_is_external);
        return string_space - 1;
    }

    allocator_type get_allocator() const noexcept { return {}; }