Define RefCount nullptr assignment operator (#1459)

If RefCount(C*) constructor becomes private, this change
will be needed to use 'foo=nullptr' syntax to clear a Pointer.

diff --git a/src/base/RefCount.h b/src/base/RefCount.h
index 60d8c2093c7fec44b3a45330aedb322eb0a8da00..782b9b52da4584ad37aa499acd1db9f519417d7d 100644 (file)
--- a/src/base/RefCount.h
+++ b/src/base/RefCount.h
@@ -66,6 +66,8 @@ public:
         return *this;
     }
 
+    RefCount &operator =(std::nullptr_t) { dereference(); return *this; }
+
     explicit operator bool() const { return p_; }
 
     bool operator !() const { return !p_; }