ipv4AsUint() does not consider IPv4-mapped-IPv6 addresses

[gaissmai]

// ipv4AsUint returns ip as a uint32.
func ipv4AsUint(ip netip.Addr) uint32 {
  bs := ip.As4()
  return binary.BigEndian.Uint32(bs[:])
}

One can argue about whether IPv4-mapped IPv6 addresses should be allowed as a prefix at all, but in the following code snippet you already pay attention to it:

func (t *Table[T]) Get(addr netip.Addr) (ret T, ok bool) {
  t.init()

  // Ideally we would use addr.AsSlice here, but AsSlice is just
  // barely complex enough that it can't be inlined, and that in
  // turn causes the slice to escape to the heap. Using As16 and
  // manual slicing here helps the compiler keep Get alloc-free.
  st := t.tableForAddr(addr)
  rawAddr := addr.As16()
  bs := rawAddr[:]
  if addr.Is4() {
    bs = bs[12:]
  }
// ...

thanks for ART