netcore/System.Private.CoreLib/src/System/Nullable.cs

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 namespace System
   6 {
   7         partial struct Nullable<T>
   8         {
   9                 //
  10                 // These are called by the JIT
  11                 //
  12
  13                 //
  14                 // JIT implementation of box valuetype System.Nullable`1<T>
  15                 //
  16                 static object? Box (T? o)
  17                 {
  18                         if (!o.hasValue)
  19                                 return null;
  20
  21                         return o.value;
  22                 }
  23
  24                 static T? Unbox (object o)
  25                 {
  26                         if (o == null)
  27                                 return null;
  28                         return (T) o;
  29                 }
  30
  31                 static T? UnboxExact (object o)
  32                 {
  33                         if (o == null)
  34                                 return null;
  35                         if (o.GetType() != typeof (T))
  36                                 throw new InvalidCastException();
  37
  38                         return (T) o;
  39                 }
  40         }
  41 }