C#: Get all derived Types from the base Type that should be able to be created via Activator.CreateInstance

        /// <summary>

        /// Get all <see cref="Type"/> from <see cref="AppDomain.CurrentDomain"/> that should be able to be created via <see cref="Activator.CreateInstance(System.Type,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo) "/>.

        /// </summary>

        /// <param name="baseType"></param>

        /// <returns></returns>

        public static IEnumerable< Type > GetTypesDerivedFrom( [CanBeNull] this Type baseType ) {

            if ( baseType == null ) {

                throw new ArgumentNullException( "baseType" );

            }

            return AppDomain.CurrentDomain.GetAssemblies()

                            .SelectMany( assembly => assembly.GetTypes(), ( assembly, type ) => type )

                            .Where( arg => baseType.IsAssignableFrom( arg ) && arg.IsClass && !arg.IsAbstract );

        }