Turn a slice of 8 boolean values into a byte (uint8).

Example for picking out only the value of the 4 least significant bits of a byte, use that value to lookup the map.

Invert the bits in an uint32.

Calculates the Prefix, and the address range for that prefix.

The gimmick here is that, unique among go's arithmetic-ish operators, << does not require that its parameters have the same type.