Question

What’s the meaning of ~0 in this code?
Can somebody analyze this code for me?

unsigned int Order(unsigned int maxPeriod = ~0) const
{
    Point r = *this;
    unsigned int n = 0;
    while( r.x_ != 0 && r.y_ != 0 )
    {
        ++n;
        r += *this;
        if ( n > maxPeriod ) break;
    }
    return n;
}

Answer 1

~0 is the bitwise complement of 0, which is a number with all bits filled. For an unsigned 32-bit int, that’s 0xffffffff. The exact number of fs will depend on the size of the value that you assign ~0 to.