source: branches/2895_PushGP_GenealogyAnalysis/HeuristicLab.Problems.ProgramSynthesis/Push.Base/Extensions/MathExtensions.cs

using System;
// ReSharper disable CompareOfFloatsByEqualityOperator

namespace HeuristicLab.Problems.ProgramSynthesis {
  public static class MathExtensions {

    public static long AbsoluteDiff(this long a, long b) {
      var diff = a - b;

      return diff == long.MinValue
        ? long.MaxValue
        : Math.Abs(diff);
    }

    public static long AbsoluteDiff(this int a, long b) {
      return AbsoluteDiff((long)a, b);
    }

    public static int AbsoluteDiff(this int a, int b) {
      var diff = a - b;

      return diff == int.MinValue
        ? int.MaxValue
        : Math.Abs(diff);
    }

    public static double AbsoluteDiff(this double a, double b) {
      var diff = a - b;

      return diff == double.MinValue || double.IsNaN(diff) || double.IsInfinity(diff)
        ? double.MaxValue
        : Math.Abs(diff);
    }

    public static int AbsoluteDiff(this char a, char b) {
      var diff = a - b;

      return diff == int.MinValue
        ? int.MaxValue
        : Math.Abs(diff);
    }
  }
}