So you've at best removed just 8 bytes for rather inconvenient programming for... LinearProbingHashTable<FooBar*, size*2> ChainHashTable<FooBar*, size>

So you've at best removed just 8 bytes for rather inconvenient programming for... LinearProbingHashTable<FooBar*, size*2> ChainHashTable<FooBar*, size> Note that linearProbingHashTable only uses 8 bytes per pointer. While ChainHashPointer still needs nextPtr, taking up 16 bytes. The *2 is for 50% load factor on linear table. But we still win on linear if we're at say 75% (simple linear) or 95% load factor (which is doable with Robin Hood)