How to determine how many bytes an integer needs?

Question

I\'m looking for the most efficient way to calculate the minimum number of bytes needed to store an integer without losing precision.

e.g.

int: 10 = 1 byte
         


        

Answer 1

Why not just use a 32-bit hash?

That will work at near-top-speed everywhere.

I'm rather confused as to why a large hash would even be wanted. If a 4-byte hash works, why not just use it always? Excepting cryptographic uses, who has hash tables with more then 2³² buckets anyway?