Improved type guessing.

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/CreateFieldAction.cs

@@ -195,11 +195,25 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				if (state != null && (state.CurrentMember.ReturnType is ParameterizedType)) {
 					var pt = (ParameterizedType)state.CurrentMember.ReturnType;
 					if (pt.FullName == "System.Collections.Generic.IEnumerable") {
-						return new [] { pt.TypeArguments.First () };
+						return new [] { pt.TypeArguments.First() };
 					}
 				}
 			}
 
+			if (expr.Parent is UnaryOperatorExpression) {
+				var uop = (UnaryOperatorExpression)expr.Parent;
+				switch (uop.Operator) {
+					case UnaryOperatorType.Not:
+						return new [] { context.Compilation.FindType(KnownTypeCode.Boolean) };
+					case UnaryOperatorType.Minus:
+					case UnaryOperatorType.Plus:
+					case UnaryOperatorType.Increment:
+					case UnaryOperatorType.Decrement:
+					case UnaryOperatorType.PostIncrement:
+					case UnaryOperatorType.PostDecrement:
+						return new [] { context.Compilation.FindType(KnownTypeCode.Int32) };
+				}
+			}
 			return Enumerable.Empty<IType>();
 		}
 		static readonly IType[] emptyTypes = new IType[0];

ICSharpCode.NRefactory.Tests/CSharp/CodeActions/CreateLocalVariableTests.cs

@@ -200,20 +200,41 @@ namespace ICSharpCode.NRefactory.CSharp.CodeActions
 
 
 		[Test()]
-		public void TestWrongContext1 ()
+		public void TestWrongContext1()
 		{
 			// May be syntactically possible, but very unlikely.
-			TestWrongContext<CreateLocalVariableAction> (
+			TestWrongContext<CreateLocalVariableAction>(
 				"using System;" + Environment.NewLine +
-					"class TestClass" + Environment.NewLine +
-					"{" + Environment.NewLine +
-					"	void Test ()" + Environment.NewLine +
-					"	{" + Environment.NewLine +
-					"		$foo();" + Environment.NewLine +
-					"	}" + Environment.NewLine +
-					"}"
+				"class TestClass" + Environment.NewLine +
+				"{" + Environment.NewLine +
+				"	void Test ()" + Environment.NewLine +
+				"	{" + Environment.NewLine +
+				"		$foo();" + Environment.NewLine +
+				"	}" + Environment.NewLine +
+				"}"
 			);
 		}
 
+		[Test()]
+		public void TestBool()
+		{
+			Test<CreateLocalVariableAction>(
+@"class TestClass
+{
+	void Test ()
+	{
+		object o = !$foo;
+	}
+}", 
+@"class TestClass
+{
+	void Test ()
+	{
+		bool foo;
+		object o = !foo;
+	}
+}");
+		}
+
 	}
 }