netcore/System.Private.CoreLib/shared/System/ByReference.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 using System.Runtime.CompilerServices;
   6 using System.Runtime.Versioning;
   7
   8 namespace System
   9 {
  10     // ByReference<T> is meant to be used to represent "ref T" fields. It is working
  11     // around lack of first class support for byref fields in C# and IL. The JIT and
  12     // type loader has special handling for it that turns it into a thin wrapper around ref T.
  13     [NonVersionable]
  14     internal readonly ref struct ByReference<T>
  15     {
  16 #pragma warning disable CA1823, 169 // private field '{blah}' is never used
  17         private readonly IntPtr _value;
  18 #pragma warning restore CA1823, 169
  19
  20         [Intrinsic]
  21         public ByReference(ref T value)
  22         {
  23             // Implemented as a JIT intrinsic - This default implementation is for
  24             // completeness and to provide a concrete error if called via reflection
  25             // or if intrinsic is missed.
  26             throw new PlatformNotSupportedException();
  27         }
  28
  29         public ref T Value
  30         {
  31             // Implemented as a JIT intrinsic - This default implementation is for
  32             // completeness and to provide a concrete error if called via reflection
  33             // or if the intrinsic is missed.
  34             [Intrinsic]
  35             get => throw new PlatformNotSupportedException();
  36         }
  37     }
  38 }