Extract toObject()

Before: 9884, 8796, 9702, 12668, 9964
After:  9874, 8796, 9694, 12634, 9970
Target: 9800, 8458, 9634, 12290, 9702

Author: bblanchon

src/ArduinoJson/Json/JsonDeserializer.hpp

@@ -78,8 +78,8 @@ class JsonDeserializer {
 
       case '{':
         if (filter.allowObject())
-          return parseObject(VariantImpl(variant, resources_).toObject(),
-                             filter, nestingLimit);
+          return parseObject(VariantImpl::toObject(variant, resources_), filter,
+                             nestingLimit);
         else
           return skipObject(nestingLimit);
 

src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp

@@ -388,7 +388,7 @@ class MsgPackDeserializer {
     ObjectImpl object;
     if (filter.allowObject()) {
       ARDUINOJSON_ASSERT(variant != 0);
-      object = VariantImpl(variant, resources_).toObject();
+      object = VariantImpl::toObject(variant, resources_);
     }
 
     for (; n; --n) {

src/ArduinoJson/Variant/VariantData.hpp

@@ -493,9 +493,15 @@ class VariantImpl {
   }
 
   ObjectImpl toObject() {
-    ARDUINOJSON_ASSERT(type() == VariantType::Null);  // must call clear() first
     if (!data_)
       return ObjectImpl();
+    return toObject(data_, resources_);
+  }
+
+  static ObjectImpl toObject(VariantData* data_, ResourceManager* resources_) {
+    ARDUINOJSON_ASSERT(data_ != nullptr);
+    ARDUINOJSON_ASSERT(data_->type == VariantType::Null);
+    ARDUINOJSON_ASSERT(resources_ != nullptr);
     data_->type = VariantType::Object;
     return ObjectImpl(new (&data_->content.asCollection) CollectionData(),
                       resources_);