multibyteAddSub

uint multibyteAddSub(char  op)(uint[]  dest,  const(uint) []  src1,
     const (uint) []  src2,  uint  carry)

pure @nogc @safe

Multi-byte addition or subtraction dest[] = src1[] + src2[] + carry (0 or 1). or dest[] = src1[] - src2[] - carry (0 or 1). Returns carry or borrow (0 or 1). Set op == '+' for addition, '-' for subtraction.