X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fclass%2Fcorlib%2FSystem%2FNullable.cs;h=b8ac671d69978cf8fbb0eb06db8344be9e803a99;hb=e2b2d181084848f3c5dde2788370db1b79893c69;hp=89fd585df5cfb330716a17ebb7e137abd8cbbd96;hpb=a3ea7ceb4d4f5e2cb8ea421313e8939640fb898c;p=mono.git

diff --git a/mcs/class/corlib/System/Nullable.cs b/mcs/class/corlib/System/Nullable.cs
index 89fd585df5c..b8ac671d699 100644
--- a/mcs/class/corlib/System/Nullable.cs
+++ b/mcs/class/corlib/System/Nullable.cs
@@ -1,7 +1,8 @@
 //
-// System.Nullable
+// System.Nullable.cs
 //
 // Martin Baulig (martin@ximian.com)
+// Marek Safar	 (marek.safar@gmail.com)
 //
 // (C) 2004 Novell, Inc.
 //
@@ -30,32 +31,43 @@
 //
 
 using System.Reflection;
-#if NET_2_0
 using System.Collections.Generic;
-#endif
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Diagnostics;
 
-#if NET_2_0
-namespace System {
+namespace System
+{
+	[ComVisible (true)]
 	public static class Nullable {
-		public static int Compare<T> (Nullable<T> left, Nullable<T> right) where T: struct
+
+#if NET_2_1
+		[ComVisible (false)]
+#endif
+		public static int Compare<T> (T? n1, T? n2) where T: struct
 		{
-			IComparable icomparable = left.value as IComparable;
-			if (icomparable == null)
-				throw new ArgumentException ("At least one object must implement IComparable.");
-			if (left.has_value == false && right.has_value == false)
-				return 0;
-			if (!left.has_value)
-				return -1;
-			if (!right.has_value)
-				return 1;
+			if (n1.has_value) {
+				if (!n2.has_value)
+					return 1;
 
-			return icomparable.CompareTo (right.value);
+				return Comparer<T>.Default.Compare (n1.value, n2.value);
+			}
+			
+			return n2.has_value ? -1 : 0;
 		}
 
-		public static bool Equals<T> (Nullable <T> value1, Nullable<T> value2) where T: struct
+#if NET_2_1
+		[ComVisible (false)]
+#endif
+		public static bool Equals<T> (T? n1, T? n2) where T: struct
 		{
-			return value1.Equals (value2);
+			if (n1.has_value != n2.has_value)
+				return false;
+
+			if (!n1.has_value)
+				return true;
+
+			return EqualityComparer<T>.Default.Equals (n1.value, n2.value);
 		}
 
 		public static Type GetUnderlyingType (Type nullableType)
@@ -70,6 +82,7 @@ namespace System {
 	}
 
 	[Serializable]
+	[DebuggerStepThrough]
 	public struct Nullable<T> where T: struct
 	{
 		#region Sync with runtime code
@@ -108,14 +121,13 @@ namespace System {
 
 		bool Equals (Nullable<T> other)
 		{
-			Nullable<T> no = (Nullable<T>) other;
-			if (no.has_value != has_value)
+			if (other.has_value != has_value)
 				return false;
 
 			if (has_value == false)
 				return true;
 
-			return no.value.Equals (value);
+			return other.value.Equals (value);
 		}
 
 		public override int GetHashCode ()
@@ -128,15 +140,12 @@ namespace System {
 
 		public T GetValueOrDefault ()
 		{
-			return GetValueOrDefault (default (T));
+			return has_value ? value : default (T);
 		}
 
-		public T GetValueOrDefault (T def_value)
+		public T GetValueOrDefault (T defaultValue)
 		{
-			if (!has_value)
-				return def_value;
-			else
-				return value;
+			return has_value ? value : defaultValue;
 		}
 
 		public override string ToString ()
@@ -157,14 +166,19 @@ namespace System {
 			return value.Value;
 		}
 
+		//
 		// These are called by the JIT
-		// Ironicly, the C#  code is the same for these two,
-		// however, on the inside they do somewhat different things
+		//
+#pragma warning disable 169
+		//
+		// JIT implementation of box valuetype System.Nullable`1<T>
+		//
 		static object Box (T? o)
 		{
-			if (o == null)
+			if (!o.has_value)
 				return null;
-			return (T) o;
+				
+			return o.value;
 		}
 		
 		static T? Unbox (object o)
@@ -173,6 +187,6 @@ namespace System {
 				return null;
 			return (T) o;
 		}
+#pragma warning restore 169
 	}
 }
-#endif