Add methods to BigInt

It is indeed intended that BigInt? should gain more functionality. It's very limited right now; the most obvious missing feature is formatting, which makes it rather useless at present. Please make a list of the desired methods, together with a link to the most appropriate documentation.

(Most of my time is taken up with getting the basics of D2 math working. I'll return to BigInt? when that's done).

From http://java.sun.com/j2se/1.4.2/docs/api/java/math/BigInteger.html

this(long);
long longValue();
int bitLength();
BigInt pow(int exponent);
bool testBit(int n);
bool setBit(int n);
bool clearBit(int n);
bool flipBit(int n);
bool testBit(int n);

Reverse overloads of the appropriate operators (all but Add and Mul) are needed. (i.e. 6 - bigint is currently an error)

Also, would it be possible to get bitwise operators (and, or, xor) as well?

You're right about the reverse overloads. I don't think bitwise operators make sense on signed BigInts?. Built-in types use 2's-complement, but BigInt? doesn't. You can define the operations to pretend that it does, but is it actually a good idea? (Actually, I'm not sure that logical operators make sense even on built-in signed types!) What are the use cases?

Note that you can say: uint [] x, uint [] y; x[] = x[] ^{y[]; so the functionality is already in the language. So the question may be, does BigUint? need to be exposed? (I hope not).}

I've now added pow() which was by far the most difficult of the requested methods. toLong() and opCall(long) are also in place, as is uintLength and ulongLength.

Not sure about bitLength, since in theory it can exceed size_t! I guess in practice, it can't. But, since BigInt? uses copy-on-write, those bit operations would be unbelievable inefficient. They can't be done with that interface.

What do you think is the better interface: BigInt? x = BigInt?(70); BigInt? y = BigInt?.pow(x, 80);

OR

BigInt? x = BigInt?(70); BigInt? y = x; y.pow(80);