From 49a9977510cf59d77512a5656b79ca657267f3f7 Mon Sep 17 00:00:00 2001
From: jwc <john@qlcorp.net>
Date: Fri, 30 Nov 2018 18:31:55 -0500
Subject: [PATCH] Add is_null iterator method

Add method to return Boolean if iterator is uninitialized
---
 include/nlohmann/detail/iterators/iter_impl.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/nlohmann/detail/iterators/iter_impl.hpp b/include/nlohmann/detail/iterators/iter_impl.hpp
index 6674c0645..aab4c5237 100644
--- a/include/nlohmann/detail/iterators/iter_impl.hpp
+++ b/include/nlohmann/detail/iterators/iter_impl.hpp
@@ -78,6 +78,11 @@ class iter_impl
     /// default constructor
     iter_impl() = default;
 
+    // test uninitialized iterator
+    bool is_null() {
+        return m_object == nullptr;
+    }
+
     /*!
     @brief constructor for a given JSON instance
     @param[in] object  pointer to a JSON object for this iterator