Since IPv4 addresses are natively a 32-bit integer at the level of BSD sockets, it makes sense to allow curl to accept them without having it be re-parsed back

Since IPv4 addresses are natively a 32-bit integer at the level of BSD sockets, it makes sense to allow curl to accept them without having it be re-parsed back out into a dotted-quad. Many tools and databases will store addresses natively this way. Let's say you were writing a script to take that information and probe it with curl; convenient to just printf("https://0x%x https://0x%x", ip_address), you know?