Type check when upcasting PassOwnPtr/PassOwnArrayPtr to avoid possible function call ambiguousness

Source/wtf/PassRefPtr.h

Index: Source/wtf/PassRefPtr.h
diff --git a/Source/wtf/PassRefPtr.h b/Source/wtf/PassRefPtr.h
index 46417573a17d5124bfcd0ebe55442edbb8c9f761..1de5e338a28708005a8d93b8835d12ecb258e936 100644
--- a/Source/wtf/PassRefPtr.h
+++ b/Source/wtf/PassRefPtr.h
@@ -25,6 +25,11 @@
 #include "wtf/NullPtr.h"
 #include "wtf/TypeTraits.h"
 
+#define EnsureRefPtrConvertibleArgDefn \

[Nico, 2013/08/29 19:58:47]

This is identical to EnsureOwnArrayPtrConvertibleArgDefn, right? Maybe some
define like this should be in TypeTraits instead?

+    typename EnableIf<IsPointerConvertible<U, T>::Value, bool>::Type
+#define EnsureRefPtrConvertibleArgDecl \
+    EnsureRefPtrConvertibleArgDefn = true
+
 namespace WTF {
 
     template<typename T> class RefPtr;
@@ -53,11 +58,11 @@ namespace WTF {
         // a const PassRefPtr. However, it makes it much easier to work with PassRefPtr
         // temporaries, and we don't have a need to use real const PassRefPtrs anyway.
         PassRefPtr(const PassRefPtr& o) : m_ptr(o.leakRef()) { }
-        template<typename U> PassRefPtr(const PassRefPtr<U>& o, EnsurePtrConvertibleArgDecl(U, T)) : m_ptr(o.leakRef()) { }
+        template<typename U> PassRefPtr(const PassRefPtr<U>& o, EnsureRefPtrConvertibleArgDecl) : m_ptr(o.leakRef()) { }
 
         ALWAYS_INLINE ~PassRefPtr() { derefIfNotNull(m_ptr); }
 
-        template<typename U> PassRefPtr(const RefPtr<U>&, EnsurePtrConvertibleArgDecl(U, T));
+        template<typename U> PassRefPtr(const RefPtr<U>&, EnsureRefPtrConvertibleArgDecl);
 
         T* get() const { return m_ptr; }
 
@@ -83,7 +88,7 @@ namespace WTF {
         mutable T* m_ptr;
     };
 
-    template<typename T> template<typename U> inline PassRefPtr<T>::PassRefPtr(const RefPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
+    template<typename T> template<typename U> inline PassRefPtr<T>::PassRefPtr(const RefPtr<U>& o, EnsureRefPtrConvertibleArgDefn)
         : m_ptr(o.get())
     {
         T* ptr = m_ptr;