Integer.cs

using System;

namespace Amoenus.NiceInteger
{
    /// <summary>
    ///     Nice helpers for Integers
    /// </summary>
    public static class Integer
    {
        /// <summary>
        ///     Determines whether dividend is divisible by the specified divisor.
        /// </summary>
        /// <param name="dividend">The dividend.</param>
        /// <param name="divisor">The divisor.</param>
        /// <returns>
        ///     <c>true</c> if is divisible by the specified divisor; otherwise, <c>false</c>.
        /// </returns>
        /// <exception cref="System.DivideByZeroException"></exception>
        public static bool IsDivisibleBy(this int dividend, int divisor)
        {
            if (divisor == 0)
                throw new DivideByZeroException();

            return ((divisor & (~divisor + 1)) == divisor
                                                ? dividend & (divisor - 1)
                                                : dividend % divisor) == 0;
        }

        /// <summary>
        ///     Determines whether dividend is odd number.
        /// </summary>
        /// <param name="dividend">The dividend.</param>
        /// <returns>
        ///     <c>true</c> if is divisible by the specified divisor; otherwise, <c>false</c>.
        /// </returns>
        public static bool IsOdd(this int dividend)
        {
            return (dividend & 0x01) != 0;
        }

        /// <summary>
        ///     Determines whether dividend is even number.
        /// </summary>
        /// <param name="dividend">The dividend.</param>
        /// <returns>
        ///     <c>true</c> if is divisible by the specified divisor; otherwise, <c>false</c>.
        /// </returns>
        public static bool IsEven(this int dividend)
        {
            return (dividend & 0x01) == 0;
        }
    }
}