class/System.Web.Mvc/System.Web.Mvc/TypeHelpers.cs

   1 /* ****************************************************************************
   2  *
   3  * Copyright (c) Microsoft Corporation. All rights reserved.
   4  *
   5  * This software is subject to the Microsoft Public License (Ms-PL).
   6  * A copy of the license can be found in the license.htm file included
   7  * in this distribution.
   8  *
   9  * You must not remove this notice, or any other, from this software.
  10  *
  11  * ***************************************************************************/
  12
  13 namespace System.Web.Mvc {
  14     using System;
  15
  16     internal static class TypeHelpers {
  17
  18         public static bool TypeAllowsNullValue(Type type) {
  19             // reference types allow null values
  20             if (!type.IsValueType) {
  21                 return true;
  22             }
  23
  24             // nullable value types allow null values
  25             // code lifted from System.Nullable.GetUnderlyingType()
  26             if (type.IsGenericType && !type.IsGenericTypeDefinition && (type.GetGenericTypeDefinition() == typeof(Nullable<>))) {
  27                 return true;
  28             }
  29
  30             // no other types allow null values
  31             return false;
  32         }
  33
  34     }
  35 }