Allow Vector<Optional> and Optional::get()

third_party/WebKit/Source/wtf/Optional.h

 // Copyright 2015 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.
 
 #ifndef Optional_h
 #define Optional_h
 
 #include "wtf/Alignment.h"
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
@@ skipping 10 matching lines @@
 //
 // Use this instead of OwnPtr for cases where you only want to conditionally
 // construct a "scope" object.
 //
 // Example:
 //   Optional<DrawingRecorder> recorder;
 //   if (shouldDraw)
 //       recorder.emplace(constructor, args, here);
 //   // recorder destroyed at end of scope
 //
+// It can be used in WTF::Vector.
+//
 // Note in particular that unlike a pointer, though, dereferencing a const
 // optional yields a const reference.
 
 template <typename T>
 class Optional final {
-    DISALLOW_NEW();
+    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
     WTF_MAKE_NONCOPYABLE(Optional);
 public:
     Optional() : m_ptr(nullptr) { }
     ~Optional()
     {
         if (m_ptr)
             m_ptr->~T();
     }
 
     typedef T* Optional::*UnspecifiedBoolType;
     operator UnspecifiedBoolType() const { return m_ptr ? &Optional::m_ptr : nullptr; }
 
     T& operator*() { ASSERT_WITH_SECURITY_IMPLICATION(m_ptr); return *m_ptr; }
     const T& operator*() const { ASSERT_WITH_SECURITY_IMPLICATION(m_ptr); return *m_ptr; }
     T* operator->() { ASSERT_WITH_SECURITY_IMPLICATION(m_ptr); return m_ptr; }
     const T* operator->() const { ASSERT_WITH_SECURITY_IMPLICATION(m_ptr); return m_ptr; }
+    T* get() { return m_ptr; }
+    const T* get() const { return m_ptr; }
 
     template <typename... Args>
     void emplace(Args&&... args)
     {
         RELEASE_ASSERT(!m_ptr);
         m_ptr = reinterpret_cast_ptr<T*>(&m_storage.buffer);
         new (m_ptr) T(std::forward<Args>(args)...);
     }
 
 private:
     T* m_ptr;
     AlignedBuffer<sizeof(T), WTF_ALIGN_OF(T)> m_storage;
 };
 
 } // namespace WTF
 
 using WTF::Optional;
 
 #endif // Optional_h