+ more test cases

src/JSON.cc

@@ -477,11 +477,6 @@ const std::string JSON::toString() const noexcept
 {
     switch (_type)
     {
-        case (value_type::null):
-        {
-            return "null";
-        }
-
         case (value_type::string):
         {
             return std::string("\"") + *_value.string + "\"";
@@ -533,6 +528,12 @@ const std::string JSON::toString() const noexcept
 
             return "{" + result + "}";
         }
+
+        // actually only value_type::null - but making the compiler happy
+        default:
+        {
+            return "null";
+        }
     }
 }
 

test/JSON_unit.cc

@@ -1394,6 +1394,21 @@ TEST_CASE("Iterators")
         JSON::iterator tmp1(j7.begin());
         JSON::const_iterator tmp2(j7.cbegin());
     }
+    {
+        JSON j_array = {0, 1, 2, 3, 4, 5};
+
+        JSON::iterator i1 = j_array.begin();
+        ++i1;
+        JSON::iterator i2(i1);
+        JSON::iterator i3;
+        i3 = i2;
+
+        JSON::const_iterator i4 = j_array.begin();
+        ++i4;
+        JSON::const_iterator i5(i4);
+        JSON::const_iterator i6;
+        i6 = i5;
+    }
 
     // iterator copy assignment
     {