How dangerous is it to compare floating point values?

Question

I know UIKit uses CGFloat because of the resolution independent coordinate system.

But every time I want to check if for example fram

Answer 1

I am using the following comparison function to compare a number of decimal places:

bool compare(const double value1, const double value2, const int precision)
{
    int64_t magnitude = static_cast(std::pow(10, precision));
    int64_t intValue1 = static_cast(value1 * magnitude);
    int64_t intValue2 = static_cast(value2 * magnitude);
    return intValue1 == intValue2;
}

// Compare 9 decimal places:
if (compare(theView.frame.origin.x, 0, 9)) {
    // do important operation
}