Imported Upstream version 4.2.0.179

Former-commit-id: 4610231f55806d2a05ed69e5ff3faa7336cc1479

external/referencesource/System.Configuration/System/Configuration/ConfigurationConverterBase.cs

@@ -0,0 +1,37 @@
+//------------------------------------------------------------------------------
+// <copyright file="ConfigurationConverterBase.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using System;
+using System.Collections;
+using System.IO;
+using System.Reflection;
+using System.Security.Permissions;
+using System.Xml;
+using System.Collections.Specialized;
+using System.Globalization;
+using System.ComponentModel;
+using System.Security;
+using System.Text;
+
+namespace System.Configuration {
+
+    public abstract class ConfigurationConverterBase : TypeConverter {
+
+        public override bool CanConvertTo(ITypeDescriptorContext ctx, Type type) {
+            return (type == typeof(string));
+        }
+        
+        public override bool CanConvertFrom(ITypeDescriptorContext ctx, Type type) {
+            return (type == typeof(string));
+        }
+
+        internal void ValidateType(object value, Type expected) {
+            if ((value != null) && (value.GetType() != expected)) {
+                throw new ArgumentException(SR.GetString(SR.Converter_unsupported_value_type, expected.Name));
+            }
+        }
+    }
+}