BigInt

A struct representing an arbitrary precision integer.

All arithmetic operations are supported, except unsigned shift right (>>>). Bitwise operations (|, &, ^, ~) are supported, and behave as if BigInt was an infinite length 2's complement number.

BigInt implements value semantics using copy-on-write. This means that assignment is cheap, but operations such as x++ will cause heap allocation. (But note that for most bigint operations, heap allocation is inevitable anyway.)

struct BigInt {

this(Range s);

this(bool isNegative, Range magnitude);

this(T x);

BigInt opAssign(T x);

BigInt opOpAssign(T y);

BigInt opBinary(T y);

auto opBinary(T y);

BigInt opBinaryRight(T y);

T opBinaryRight(T x);

BigInt opUnary();

bool opEquals(BigInt y);

bool opEquals(T y);

T opCast();

int opCmp(BigInt y);

int opCmp(T y);

long toLong();

int toInt();

size_t uintLength [@property getter];

size_t ulongLength [@property getter];

void toString(Writer sink, string formatString);

void toString(Writer sink, FormatSpec!char f);

void toString(void delegate(scope const(char)[]) sink, string formatString);

void toString(void delegate(scope const(char)[]) sink, FormatSpec!char f);

size_t toHash();

T getDigit(size_t n);

}

Constructors

this this(Range s): Construct a BigInt from a decimal or hexadecimal string. The number must be in the form of a decimal or hex literal. It may have a leading + or - sign, followed by 0x or 0X if hexadecimal. Underscores are permitted in any location after the 0x and/or the sign of the number.
this this(bool isNegative, Range magnitude): Construct a BigInt from a sign and a magnitude.
this this(T x): Construct a BigInt from a built-in integral type.
this this(T x): Construct a BigInt from another BigInt.

Members

Functions

getDigit T getDigit(size_t n): Gets the nth number in the underlying representation that makes up the whole BigInt.
opAssign BigInt opAssign(T x): Assignment from built-in integer types.
opAssign BigInt opAssign(T x): Assignment from another BigInt.
opBinary BigInt opBinary(T y): Implements binary operators between BigInts.
opBinary BigInt opBinary(T y): Implements binary operators between BigInt's and built-in integers.
opBinary auto opBinary(T y): Implements a narrowing remainder operation with built-in integer types.
opBinaryRight BigInt opBinaryRight(T y)
T opBinaryRight(T x): Implements operators with built-in integers on the left-hand side and BigInt on the right-hand side.
opCast T opCast(): Implements casting to bool.
opCast T opCast(): Implements casting to integer types.
opCast T opCast(): Implements casting to floating point types.
opCast T opCast(): Implements casting to/from qualified BigInt's.
opCmp int opCmp(BigInt y)
int opCmp(T y): Implements 3-way comparisons of BigInt with BigInt or BigInt with built-in numeric types.
opEquals bool opEquals(BigInt y)
bool opEquals(T y): Implements BigInt equality test with other BigInt's and built-in numeric types.
opOpAssign BigInt opOpAssign(T y): Implements assignment operators from built-in integers of the form BigInt op= integer.
opOpAssign BigInt opOpAssign(T y): Implements assignment operators of the form BigInt op= BigInt.
opUnary BigInt opUnary(): Implements BigInt unary operators.
toHash size_t toHash()
toInt int toInt()
toLong long toLong()
toString void toString(Writer sink, string formatString)
void toString(Writer sink, FormatSpec!char f)
void toString(void delegate(scope const(char)[]) sink, string formatString)
void toString(void delegate(scope const(char)[]) sink, FormatSpec!char f): Convert the BigInt to string, passing it to the given sink.

Properties

uintLength size_t uintLength [@property getter]: Number of significant uints which are used in storing this number. The absolute value of this BigInt is always < 2^{32*uintLength}
ulongLength size_t ulongLength [@property getter]: Number of significant ulongs which are used in storing this number. The absolute value of this BigInt is always < 2^{64*ulongLength}

Examples

BigInt a = "9588669891916142";
BigInt b = "7452469135154800";
auto c = a * b;
assert(c == BigInt("71459266416693160362545788781600"));
auto d = b * a;
assert(d == BigInt("71459266416693160362545788781600"));
assert(d == c);
d = c * BigInt("794628672112");
assert(d == BigInt("56783581982794522489042432639320434378739200"));
auto e = c + d;
assert(e == BigInt("56783581982865981755459125799682980167520800"));
auto f = d + c;
assert(f == e);
auto g = f - c;
assert(g == d);
g = f - d;
assert(g == c);
e = 12345678;
g = c + e;
auto h = g / b;
auto i = g % b;
assert(h == a);
assert(i == e);
BigInt j = "-0x9A56_57f4_7B83_AB78";
BigInt k = j;
j ^^= 11;
assert(k ^^ 11 == j);