Trait spl_math::checked_ceil_div::CheckedCeilDiv

source ·

pub trait CheckedCeilDiv: Sized {
    // Required method
    fn checked_ceil_div(&self, rhs: Self) -> Option<(Self, Self)>;
}

Expand description

Perform a division that does not truncate value from either side, returning the (quotient, divisor) as a tuple

When dividing integers, we are often left with a remainder, which can cause information to be lost. By checking for a remainder, adjusting the quotient, and recalculating the divisor, this provides the most fair calculation.

For example, 400 / 32 = 12, with a remainder cutting off 0.5 of amount. If we simply ceiling the quotient to 13, then we’re saying 400 / 32 = 13, which also cuts off value. To improve this result, we calculate the other way around and again check for a remainder: 400 / 13 = 30, with a remainder of 0.77, and we ceiling that value again. This gives us a final calculation of 400 / 31 = 13, which provides a ceiling calculation without cutting off more value than needed.

This calculation fails if the divisor is larger than the dividend, to avoid having a result like: 1 / 1000 = 1.