====== Bit functions ======

These functions are for bit math.

===== Powers of two =====

  * ''int npo2(int x)'' -- returns the next lowest power of 2 greater or equal to X.
  * ''int bitlog2(int x)'' -- returns the index of the highest used bit, aka integer binary logarithm. Useful to convert flags like ''1<<8 = 256'' back into ''8''.

===== Working with bit arrays =====

These functions allow you to work with variables as if they were arrays of bits:

  * ''bool getbit(int a, int i)'' -- returns bit ''a[i]''.
  * ''int setbit(int a, int i)'' -- performs ''a[i] = 1'' and returns the result.
  * ''int clrbit(int a, int i)'' -- performs ''a[i] = 0'' and returns the result.
  * ''int tglbit(int a, int i)'' -- performs ''a[i] = !a[i]'' and returns the result.

===== Unsetting bit flags =====

''void notflag(int flags, int flag)''

Bit flags can be applied using ''flags & SOMEFLAG''. But removing them requires a more complicated expression ''!(flags & SOMEFLAG)''.

''notflag(flags, SOMEFLAG)'' unsets SOMEFLAG, shorthand for ''!(flags & SOMEFLAG)''.