Use SFNIAE in JsonArray

bblanchon · Aug 9, 2023 · 2aba467 · 2aba467
1 parent 1346f78
commit 2aba467
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 8 deletions.
diff --git a/src/ArduinoJson/Array/JsonArray.hpp b/src/ArduinoJson/Array/JsonArray.hpp
@@ -45,10 +45,21 @@ class JsonArray : public detail::VariantOperators<JsonArray> {
   // Returns a reference to the new element.
   // https://arduinojson.org/v6/api/jsonarray/add/
   template <typename T>
-  JsonVariant add() const {
+  typename detail::enable_if<!detail::is_same<T, JsonVariant>::value, T>::type
+  add() const {
     return add<JsonVariant>().to<T>();
   }
 
+  // Appends a new (null) element to the array.
+  // Returns a reference to the new element.
+  // https://arduinojson.org/v6/api/jsonarray/add/
+  template <typename T>
+  typename detail::enable_if<detail::is_same<T, JsonVariant>::value, T>::type
+  add() const {
+    return JsonVariant(detail::ArrayData::addElement(data_, resources_),
+                       resources_);
+  }
+
   // Appends a value to the array.
   // https://arduinojson.org/v6/api/jsonarray/add/
   template <typename T>
@@ -174,12 +185,6 @@ class JsonArray : public detail::VariantOperators<JsonArray> {
   detail::ResourceManager* resources_;
 };
 
-template <>
-inline JsonVariant JsonArray::add<JsonVariant>() const {
-  return JsonVariant(detail::ArrayData::addElement(data_, resources_),
-                     resources_);
-}
-
 ARDUINOJSON_END_PUBLIC_NAMESPACE
 
 ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE

diff --git a/src/ArduinoJson/Variant/VariantRefBase.hpp b/src/ArduinoJson/Variant/VariantRefBase.hpp
@@ -144,7 +144,7 @@ class VariantRefBase : public VariantTag {
     return add<JsonVariant>().template to<T>();
   }
 
-  // Appends a new (empty) element to the array.
+  // Appends a new (null) element to the array.
   // Returns a reference to the new element.
   // https://arduinojson.org/v6/api/jsonvariant/add/
   template <typename T>