sMath Namespace Reference

simple mathematical functions, mostly templated

Functions
template<typename T >
const T &	max (const T &a, const T &b)
	maximum of 2 values
template<typename T >
const T &	min (const T &a, const T &b)
	minimum of 2 values
template<typename T >
const T &	constrain (T &x, const T &a, const T &b)
template<typename T >
const T &	max (const T &a, const T &b, const T &c)
	maximum of three arguments
template<typename T >
const T &	min (const T &a, const T &b, const T &c)
	minimum of three arguments
template<typename T >
int	sign (const T &a)
	the sign of a number
template<typename T >
T	sqr (const T &a)
	square of a number
template<typename T >
T	cub (const T &a)
	cube of a number
template<typename T >
T	quad (const T &a)
	fourth power of a number
template<typename T >
T	powerN (const T &a, unsigned int n)
	power of a by positive integer exponent n
template<typename T >
T	power (const T &a, const int n)
	power of by integer exponent n
template<typename T >
T	nextPowerOf2 (T n)
	power of by integer exponent n
template<typename T >
void	swap (T &a, T &b)
	swap two numbers
template<typename T >
std::string	repr (T &x)
	return the usual base-10 representation of a number
template<typename T >
int	digit (T x, const int p)
	extract a 10-decimal digit form a number: More...
void	copyBytes (void *dest, const void *src, const unsigned cnt)
	copy bytes
unsigned int	count_bits (uint32_t v)
	number of '1' bits in a 32-bits integer (Charlie Gordon & Don Clugston) More...
template<typename T >
unsigned int	count_bits2 (T v)
	number of '1' bits, from: http://graphics.stanford.edu/~seander/bithacks.html More...

Function Documentation

unsigned int sMath::count_bits ( uint32_t  v )

inline

Should use Intel SIMD instruction POPCNT

unsigned int sMath::count_bits2

(

T

v

)

Works up to 128 bits

int sMath::digit ( T  x, const int  p  )

inline

1st digit is really the first one, we do not start at zero