Move base::WeakPtrFactory's ctor and dtor out-of-line

base/memory/weak_ptr.h

 // Copyright (c) 2012 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.
 
 // Weak pointers are pointers to an object that do not affect its lifetime,
 // and which may be invalidated (i.e. reset to nullptr) by the object, or its
 // owner, at any time, most commonly when the object is about to be deleted.
 
 // Weak pointers are useful when an object needs to be accessed safely by one
 // or more objects other than its owner, and those callers can cope with the
@@ skipping 257 matching lines @@
 }
 template <class T>
 bool operator==(const WeakPtr<T>& weak_ptr, std::nullptr_t) {
   return weak_ptr.get() == nullptr;
 }
 template <class T>
 bool operator==(std::nullptr_t, const WeakPtr<T>& weak_ptr) {
   return weak_ptr == nullptr;
 }
 
+namespace internal {
+class BASE_EXPORT WeakPtrFactoryBase {
+ protected:
+  WeakPtrFactoryBase(uintptr_t ptr);
+  ~WeakPtrFactoryBase();
+  internal::WeakReferenceOwner weak_reference_owner_;
+  uintptr_t ptr_;
+};
+}  // namespace internal
+
 // A class may be composed of a WeakPtrFactory and thereby
 // control how it exposes weak pointers to itself.  This is helpful if you only
 // need weak pointers within the implementation of a class.  This class is also
 // useful when working with primitive types.  For example, you could have a
 // WeakPtrFactory<bool> that is used to pass around a weak reference to a bool.
 template <class T>
-class WeakPtrFactory {
+class WeakPtrFactory : public internal::WeakPtrFactoryBase {
  public:
-  explicit WeakPtrFactory(T* ptr) : ptr_(ptr) {
-  }
+  explicit WeakPtrFactory(T* ptr)
+      : WeakPtrFactoryBase(reinterpret_cast<uintptr_t>(ptr)) {}
 
-  ~WeakPtrFactory() { ptr_ = nullptr; }
+  ~WeakPtrFactory() {}
 
   WeakPtr<T> GetWeakPtr() {
     DCHECK(ptr_);
-    return WeakPtr<T>(weak_reference_owner_.GetRef(), ptr_);
+    return WeakPtr<T>(weak_reference_owner_.GetRef(),
+                      reinterpret_cast<T*>(ptr_));
   }
 
   // Call this method to invalidate all existing weak pointers.
   void InvalidateWeakPtrs() {
     DCHECK(ptr_);
     weak_reference_owner_.Invalidate();
   }
 
   // Call this method to determine if any weak pointers exist.
   bool HasWeakPtrs() const {
     DCHECK(ptr_);
     return weak_reference_owner_.HasRefs();
   }
 
  private:
-  internal::WeakReferenceOwner weak_reference_owner_;
-  T* ptr_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(WeakPtrFactory);
 };
 
 // A class may extend from SupportsWeakPtr to let others take weak pointers to
 // it. This avoids the class itself implementing boilerplate to dispense weak
 // pointers.  However, since SupportsWeakPtr's destructor won't invalidate
 // weak pointers to the class until after the derived class' members have been
 // destroyed, its use can lead to subtle use-after-destroy issues.
 template <class T>
 class SupportsWeakPtr : public internal::SupportsWeakPtrBase {
@@ skipping 31 matching lines @@
 //   base::WeakPtr<Derived> ptr = derived.AsWeakPtr();  // Fails.
 
 template <typename Derived>
 WeakPtr<Derived> AsWeakPtr(Derived* t) {
   return internal::SupportsWeakPtrBase::StaticAsWeakPtr<Derived>(t);
 }
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_WEAK_PTR_H_