Move both instances of address_of into stl_util.

base/stl_util.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Derived from google3/util/gtl/stl_util.h
 
 #ifndef BASE_STL_UTIL_H_
 #define BASE_STL_UTIL_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
+// Return the address of an object as a unary functor.
+// Can be used with std::transform to make a container of pointers from a
+// container of objects.
+// NOTE: Does not work around the possibility that operator & is overloaded.
+template<typename T>
+T* address_of(T& v) {
+  return &v;
+}
+template<typename T>
+const T* const_address_of(const T& v) {
+  return &v;
+}
+
 // Clear internal memory of an STL object.
 // STL clear()/reserve(0) does not always free internal memory allocated
 // This function uses swap/destructor to ensure the internal memory is freed.
 template<class T> void STLClearObject(T* obj) {
   T tmp;
   tmp.swap(*obj);
   // Sometimes "T tmp" allocates objects with memory (arena implementation?).
   // Hence using additional reserve(0) even if it doesn't always work.
   obj->reserve(0);
 }
@@ skipping 165 matching lines @@
 };
 
 // Test to see if a set, map, hash_set or hash_map contains a particular key.
 // Returns true if the key is in the collection.
 template <typename Collection, typename Key>
 bool ContainsKey(const Collection& collection, const Key& key) {
   return collection.find(key) != collection.end();
 }
 
 #endif  // BASE_STL_UTIL_H_