how to compare to float number?

[fantasy2004]

Hi, all

I have a question about how to compare two float.
the follows is my code

template < class T >
class MyPoint
{
public:
    typedef typename MyPoint<T> Point;
public:
    Point(T x,T y) { this->x = x; this->y = y; };
    friend bool operator < ( const Point & left, const Point & right )
    {
        if ( left.x != right.x )
        {
            return ( left.x < right.x );
        }
        else
        {
            return ( left.y < right.y );
        }
    }
public:
    T x,y;
};
int main()
{
    typedef MyPoint<float> POINT;

    set < POINT > point;
    point.insert( POINT(1.0,1.0) );
    point.insert( POINT(0.0,0.0) );

   
    set < POINT > :: iterator it;

    it = point.find( POINT(1.00000005,1.0) );
    if ( it == point.end() )
    {
        cout << "not found\n";
    }
    else
    {
        cout << it->x<< " " << it->y << "\n";
    }
    return 0;
}

I found that POINT(1.00000005,1.0) is the equal to POINT(1.0,1.0) ,
but some times I want to get the result POINT(1.000001,1.0) == POINT(1.0,1.0) be true.

what is the better way to do this?