using System;

public class Program

{

    public static void Main()

    {

        Test a = Test.A;

        Test ab = ToEnum<Test>(3);

        Console.WriteLine($"a = {a}");

        Console.WriteLine($"ab = {ab}");

    }

    public static TEnum ToEnum<TEnum>(int value) where TEnum : Enum 

    {

        return (TEnum) (object) value;

    }

    public enum Test {

        A = 1,

        B = 2,

        C = 4

    }

}