RoundedUpDivision.swift

extension FixedWidthInteger where Self: SignedInteger {
    func roundedUpDivision(by divisor: Self) throws -> Self {
        guard divisor != .zero else {
            throw Division.Error.divideByZero
        }
        guard !(self == .min && divisor == -1) else {
            throw Division.Error.overflow
        }
        let roundedTowardsZeroQuotient = self / divisor
        if isMultiple(of: divisor) { return roundedTowardsZeroQuotient }
        return (divisor > .zero) == (self > .zero) ?
            roundedTowardsZeroQuotient + 1 :
            roundedTowardsZeroQuotient
    }
}

struct Division {
    enum Error: Swift.Error {
        case divideByZero
        case overflow
    }
}