Keep only base/extractor.[cc|h].

base/type_utils.h

-// Copyright 2005-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-#ifndef OMAHA_COMMON_TYPE_UTILS_H_
-#define OMAHA_COMMON_TYPE_UTILS_H_
-
-namespace omaha {
-
-//
-// Detecting convertibility and inheritence at compile time
-// (Extracted from: Modern C++ Design)
-//
-
-// Evaluates true if U inherites from T publically, or if T and U are same type
-#define SUPERSUBCLASS(T, U) \
-  (ConversionUtil<const U*, const T*>::exists && \
-  !ConversionUtil<const T*, const void*>::same_type)
-
-// Evaluates true only if U inherites from T publically
-#define SUPERSUBCLASS_STRICT(T, U) \
-  (SUPERSUBCLASS(T, U) && \
-  !ConversionUtil<const T, const U>::same_type)
-
-// Perform type test
-template <class T, class U>
-class ConversionUtil {
- private:
-  typedef char Small;
-  class Big {
-    char dummy[2];
-  };
-  static Small Test(U);
-  static Big Test(...);
-  static T MakeT();
-
- public:
-  // Tell whether there is ConversionUtil from T to U
-  enum { exists = sizeof(Test(MakeT())) == sizeof(Small) };
-
-  // Tells whether there are ConversionUtils between T and U in both directions
-  enum { exists_2way = exists && ConversionUtil<U, T>::exists };
-
-  // Tells whether there are same type
-  enum { same_type = false };
-};
-
-// Perform same type test through partial template specialization
-template<class T>
-class ConversionUtil<T, T> {
- public:
-  enum { exists = 1, exists_2way = 1, same_type = 1 };
-};
-
-}  // namespace omaha
-
-#endif  // OMAHA_COMMON_TYPE_UTILS_H_