Allow explicit conversion operators and implement WTF::OwnPtr::operator bool.

third_party/WebKit/Source/wtf/OwnPtr.h

 /*
  *  Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *  Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
@@ skipping 52 matching lines @@
     void clear();
     PassOwnPtr<T> release();
     PtrType leakPtr() WARN_UNUSED_RETURN;
 
     ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }
     PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
 
     ValueType& operator[](std::ptrdiff_t i) const;
 
     bool operator!() const { return !m_ptr; }
-
-    // This conversion operator allows implicit conversion to bool but not to
-    // other integer types.
-    typedef PtrType OwnPtr::*UnspecifiedBoolType;
-    operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; }
+    explicit operator bool() const { return m_ptr; }
 
     OwnPtr& operator=(const PassOwnPtr<T>&);
     OwnPtr& operator=(std::nullptr_t) { clear(); return *this; }
     template <typename U> OwnPtr& operator=(const PassOwnPtr<U>&);
 
     OwnPtr(OwnPtr&&);
     template <typename U> OwnPtr(OwnPtr<U>&&);
 
     OwnPtr& operator=(OwnPtr&&);
     template <typename U> OwnPtr& operator=(OwnPtr<U>&&);
@@ skipping 153 matching lines @@
 template <typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p)
 {
     return p.get();
 }
 
 } // namespace WTF
 
 using WTF::OwnPtr;
 
 #endif // WTF_OwnPtr_h