1 files changed, 133 insertions, 0 deletions
diff --git a/src/mscorlib/src/Microsoft/Win32/OAVariantLib.cs b/src/mscorlib/src/Microsoft/Win32/OAVariantLib.cs
new file mode 100644
index 0000000000..8aa9f97586
--- /dev/null
+++ b/src/mscorlib/src/Microsoft/Win32/OAVariantLib.cs
@@ -0,0 +1,133 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+/*============================================================
+**
+**
+**
+** Purpose: This class only exists to provide support for 
+**          implenting IDispatch on managed objects. It is 
+**          used to provide OleAut style coercion rules.
+**
+** 
+===========================================================*/
+namespace Microsoft.Win32 {
+    
+    using System;
+    using System.Diagnostics.Contracts;
+    using System.Reflection;
+    using System.Runtime.CompilerServices;
+    using System.Runtime.Versioning;
+    using CultureInfo = System.Globalization.CultureInfo;
+
+    internal static class OAVariantLib
+    {
+        #region Constants
+
+        // Constants for VariantChangeType from OleAuto.h
+        public const int NoValueProp = 0x01;
+        public const int AlphaBool = 0x02;
+        public const int NoUserOverride = 0x04;
+        public const int CalendarHijri = 0x08;
+        public const int LocalBool = 0x10;
+        
+        internal static readonly Type [] ClassTypes = {
+            typeof(Empty),
+            typeof(void),
+            typeof(Boolean),
+            typeof(Char),
+            typeof(SByte),
+            typeof(Byte),
+            typeof(Int16),
+            typeof(UInt16),
+            typeof(Int32),
+            typeof(UInt32),
+            typeof(Int64),
+            typeof(UInt64),
+            typeof(Single),
+            typeof(Double),
+            typeof(String),
+            typeof(void),
+            typeof(DateTime),
+            typeof(TimeSpan),
+            typeof(Object),
+            typeof(Decimal),
+            null,  // Enums - what do we do here?
+            typeof(Missing),
+            typeof(DBNull),
+        };
+
+    	// Keep these numbers in sync w/ the above array.
+        private const int CV_OBJECT=0x12;
+        
+        #endregion
+
+        
+        #region Internal Methods
+
+        /**
+         * Changes a Variant from one type to another, calling the OLE
+         * Automation VariantChangeTypeEx routine.  Note the legal types here are
+         * restricted to the subset of what can be legally found in a VB
+         * Variant and the types that CLR supports explicitly in the 
+         * CLR Variant class.  
+         */
+        [System.Security.SecurityCritical]  // auto-generated
+        internal static Variant ChangeType(Variant source, Type targetClass, short options, CultureInfo culture)
+        {
+            if (targetClass == null)
+                throw new ArgumentNullException("targetClass");
+            if (culture == null)
+                throw new ArgumentNullException("culture");
+            Variant result = new Variant ();
+            ChangeTypeEx(ref result, ref source, 
+#if FEATURE_USE_LCID
+                         culture.LCID, 
+#else
+        // @CORESYSTODO: what does CoreSystem expect for this argument?
+                        0,
+#endif
+                         targetClass.TypeHandle.Value, GetCVTypeFromClass(targetClass), options);
+            return result;
+        }       
+
+        #endregion
+
+
+        #region Private Helpers
+
+        private static int GetCVTypeFromClass(Type ctype) 
+        {
+            Contract.Requires(ctype != null);
+#if _DEBUG
+            BCLDebug.Assert(ClassTypes[CV_OBJECT] == typeof(Object), "OAVariantLib::ClassTypes[CV_OBJECT] == Object.class");
+#endif
+    
+            int cvtype=-1;
+            for (int i=0; i<ClassTypes.Length; i++) {
+                if (ctype.Equals(ClassTypes[i])) {
+                    cvtype=i;
+                    break;
+                }
+            }
+    
+            // OleAut Binder works better if unrecognized
+            // types were changed to Object.  So don't throw here.
+            if (cvtype == -1)
+                cvtype = CV_OBJECT;
+    
+            return cvtype;
+        }
+
+        #endregion
+
+
+        #region Private FCalls
+
+        [System.Security.SecurityCritical]  // auto-generated
+        [MethodImplAttribute(MethodImplOptions.InternalCall)]
+        private static extern void ChangeTypeEx(ref Variant result, ref Variant source, int lcid, IntPtr typeHandle, int cvType, short flags);
+
+        #endregion
+    }
+}