src: replace NULL with nullptr

Now that we are building with C++11 features enabled, replace use
of NULL with nullptr.

The benefit of using nullptr is that it can never be confused for
an integral type because it does not support implicit conversions
to integral types except boolean - unlike NULL, which is defined
as a literal `0`.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/stream_wrap.h b/src/stream_wrap.h
index adf457e2a1..3c058d26f8 100644
--- a/src/stream_wrap.h
+++ b/src/stream_wrap.h
@@ -164,7 +164,7 @@ class StreamWrap : public HandleWrap {
     if (!callbacks_gc_ && callbacks_ != &default_callbacks_) {
       delete callbacks_;
     }
-    callbacks_ = NULL;
+    callbacks_ = nullptr;
   }
 
   void StateChange() { }