using System;

using System.Collections.Generic;

using System.Linq;

​

Console.WriteLine(A.IntToEnum<Bla>(100));

enum Bla

{

    A = 0,

    B = 100

}

​

public static class A

{

    public static TEnum IntToEnum<TEnum>(int i)

        where TEnum : Enum

    {

        Array array = Enum.GetValues(typeof(TEnum));

        int[] intValues = (int[])array;

        TEnum[] enumValues = (TEnum[])array;

        var b = intValues.Zip(enumValues);

        //Consider saving the dictionary to avoid recreating each time

        var c = b.ToDictionary<(int n, TEnum e), int, TEnum>(p => p.n, p => p.e);

        return c[i]; //KeyNotFoundException possible here

    }

}