lsst::sphgeom::BigInteger Class Reference

#include <BigInteger.h>

Public Member Functions
	BigInteger (std::uint32_t *digits, unsigned capacity)
BigInteger &	operator= (BigInteger const &b)
int	getSign () const
unsigned	getSize () const
	getSize returns the number of digits in the value of this integer.
unsigned	getCapacity () const
std::uint32_t const *	getDigits () const
	getDigits returns the underlying digit array.
void	setToZero ()
	setToZero sets this integer to zero.
void	setTo (std::int64_t x)
	setTo sets this integer to the given signed 64 bit integer value.
void	setTo (std::uint64_t x)
	setTo sets this integer to the given unsigned 64 bit integer value.
void	negate ()
	negate multiplies this integer by -1.
BigInteger &	add (BigInteger const &b)
	add adds b to this integer.
BigInteger &	subtract (BigInteger const &b)
	subtract subtracts b from this integer.
BigInteger &	multiplyPow2 (unsigned n)
	multiplyPow2 multiplies this integer by 2ⁿ.
BigInteger &	multiply (BigInteger const &b)
	multiply multiplies this integer by b.

Detailed Description

BigInteger is an arbitrary precision signed integer class. It is intended to be used in applications which need relatively small integers, and only supports addition, subtraction and multiplication.

Internally, a BigInteger consists of a sign and an unsigned magnitude. The magnitude is represented by an array of 32 bit digits, stored from least to most significant. All non-zero integers have at least one digit, the most significant of which is non-zero. Zero is defined to have no digits.

Constructor & Destructor Documentation

BigInteger()

lsst::sphgeom::BigInteger::BigInteger ( std::uint32_t * digits, unsigned capacity )

inline

This constructor creates a zero-valued integer with the given digit array.

Member Function Documentation

getCapacity()

unsigned lsst::sphgeom::BigInteger::getCapacity ( ) const

inline

getCapacity returns the number of digits in the underlying digit array.

getSign()

int lsst::sphgeom::BigInteger::getSign ( ) const

inline

getSign returns -1, 0 or 1 if this integer is negative, zero or positive.

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The documentation for this class was generated from the following files:

• include/lsst/sphgeom/BigInteger.h
• src/BigInteger.cc