diff --git a/src/ArduinoJson/Collection/CollectionImpl.hpp b/src/ArduinoJson/Collection/CollectionImpl.hpp
index 6d708529..0e77fe35 100644
--- a/src/ArduinoJson/Collection/CollectionImpl.hpp
+++ b/src/ArduinoJson/Collection/CollectionImpl.hpp
@@ -37,10 +37,14 @@ template <typename TAdaptedString>
 inline VariantData* CollectionData::addMember(TAdaptedString key,
                                               MemoryPool* pool) {
   VariantSlot* slot = addSlot(pool);
-  if (!slotSetKey(slot, key, pool)) {
+  if (!slot)
+    return 0;
+  auto storedKey = storeString(pool, key);
+  if (!storedKey) {
     removeSlot(slot);
     return 0;
   }
+  slot->setKey(storedKey);
   return slot->data();
 }
 
diff --git a/src/ArduinoJson/Memory/MemoryPool.hpp b/src/ArduinoJson/Memory/MemoryPool.hpp
index cd8a15d8..2ea1d68b 100644
--- a/src/ArduinoJson/Memory/MemoryPool.hpp
+++ b/src/ArduinoJson/Memory/MemoryPool.hpp
@@ -273,35 +273,30 @@ class MemoryPool {
   StringNode* _strings = nullptr;
 };
 
-template <typename TAdaptedString, typename TCallback>
-bool storeString(MemoryPool* pool, TAdaptedString str,
-                 StringStoragePolicy::Copy, TCallback callback) {
-  const char* copy = pool->saveString(str);
-  JsonString storedString(copy, str.size(), JsonString::Copied);
-  callback(storedString);
-  return copy != 0;
+template <typename TAdaptedString>
+JsonString storeString(MemoryPool* pool, TAdaptedString str,
+                       StringStoragePolicy::Copy) {
+  return JsonString(pool->saveString(str), str.size(), JsonString::Copied);
 }
 
-template <typename TAdaptedString, typename TCallback>
-bool storeString(MemoryPool*, TAdaptedString str, StringStoragePolicy::Link,
-                 TCallback callback) {
-  JsonString storedString(str.data(), str.size(), JsonString::Linked);
-  callback(storedString);
-  return !str.isNull();
+template <typename TAdaptedString>
+JsonString storeString(MemoryPool*, TAdaptedString str,
+                       StringStoragePolicy::Link) {
+  return JsonString(str.data(), str.size(), JsonString::Linked);
 }
 
-template <typename TAdaptedString, typename TCallback>
-bool storeString(MemoryPool* pool, TAdaptedString str,
-                 StringStoragePolicy::LinkOrCopy policy, TCallback callback) {
+template <typename TAdaptedString>
+JsonString storeString(MemoryPool* pool, TAdaptedString str,
+                       StringStoragePolicy::LinkOrCopy policy) {
   if (policy.link)
-    return storeString(pool, str, StringStoragePolicy::Link(), callback);
+    return storeString(pool, str, StringStoragePolicy::Link());
   else
-    return storeString(pool, str, StringStoragePolicy::Copy(), callback);
+    return storeString(pool, str, StringStoragePolicy::Copy());
 }
 
-template <typename TAdaptedString, typename TCallback>
-bool storeString(MemoryPool* pool, TAdaptedString str, TCallback callback) {
-  return storeString(pool, str, str.storagePolicy(), callback);
+template <typename TAdaptedString>
+JsonString storeString(MemoryPool* pool, TAdaptedString str) {
+  return storeString(pool, str, str.storagePolicy());
 }
 
 ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Variant/ConverterImpl.hpp b/src/ArduinoJson/Variant/ConverterImpl.hpp
index 87c17417..8095cc30 100644
--- a/src/ArduinoJson/Variant/ConverterImpl.hpp
+++ b/src/ArduinoJson/Variant/ConverterImpl.hpp
@@ -153,12 +153,12 @@ struct Converter<JsonString> : private detail::VariantAttorney {
 };
 
 template <typename T>
-inline typename detail::enable_if<detail::IsString<T>::value, bool>::type
+inline typename detail::enable_if<detail::IsString<T>::value>::type
 convertToJson(const T& src, JsonVariant dst) {
   using namespace detail;
   auto data = VariantAttorney::getData(dst);
   auto pool = VariantAttorney::getPool(dst);
-  return variantSetString(data, adaptString(src), pool);
+  variantSetString(data, adaptString(src), pool);
 }
 
 template <>
diff --git a/src/ArduinoJson/Variant/SlotFunctions.hpp b/src/ArduinoJson/Variant/SlotFunctions.hpp
index 41ae51d0..29102c92 100644
--- a/src/ArduinoJson/Variant/SlotFunctions.hpp
+++ b/src/ArduinoJson/Variant/SlotFunctions.hpp
@@ -9,27 +9,6 @@
 
 ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
 
-struct SlotKeySetter {
-  SlotKeySetter(VariantSlot* instance) : _instance(instance) {}
-
-  template <typename TStoredString>
-  void operator()(TStoredString s) {
-    if (!s)
-      return;
-    ARDUINOJSON_ASSERT(_instance != 0);
-    _instance->setKey(s);
-  }
-
-  VariantSlot* _instance;
-};
-
-template <typename TAdaptedString>
-inline bool slotSetKey(VariantSlot* var, TAdaptedString key, MemoryPool* pool) {
-  if (!var)
-    return false;
-  return storeString(pool, key, SlotKeySetter(var));
-}
-
 inline size_t slotSize(const VariantSlot* var) {
   size_t n = 0;
   while (var) {
diff --git a/src/ArduinoJson/Variant/VariantData.hpp b/src/ArduinoJson/Variant/VariantData.hpp
index a5c3a0d1..b61774d1 100644
--- a/src/ArduinoJson/Variant/VariantData.hpp
+++ b/src/ArduinoJson/Variant/VariantData.hpp
@@ -284,35 +284,11 @@ class VariantData {
     return _flags & VALUE_MASK;
   }
 
-  template <typename TAdaptedString>
-  inline bool setString(TAdaptedString value, MemoryPool* pool) {
-    if (value.isNull()) {
-      setNull();
-      return true;
-    }
-
-    return storeString(pool, value, VariantStringSetter(this));
-  }
-
  private:
   void setType(uint8_t t) {
     _flags &= OWNED_KEY_BIT;
     _flags |= t;
   }
-
-  struct VariantStringSetter {
-    VariantStringSetter(VariantData* instance) : _instance(instance) {}
-
-    template <typename TStoredString>
-    void operator()(TStoredString s) {
-      if (s)
-        _instance->setString(s);
-      else
-        _instance->setNull();
-    }
-
-    VariantData* _instance;
-  };
 };
 
 ARDUINOJSON_END_PRIVATE_NAMESPACE
diff --git a/src/ArduinoJson/Variant/VariantFunctions.hpp b/src/ArduinoJson/Variant/VariantFunctions.hpp
index c0c91957..6191b650 100644
--- a/src/ArduinoJson/Variant/VariantFunctions.hpp
+++ b/src/ArduinoJson/Variant/VariantFunctions.hpp
@@ -38,9 +38,15 @@ inline void variantSetNull(VariantData* var) {
 }
 
 template <typename TAdaptedString>
-inline bool variantSetString(VariantData* var, TAdaptedString value,
+inline void variantSetString(VariantData* var, TAdaptedString value,
                              MemoryPool* pool) {
-  return var != 0 ? var->setString(value, pool) : 0;
+  if (!var)
+    return;
+  JsonString str = storeString(pool, value);
+  if (str)
+    var->setString(str);
+  else
+    var->setNull();
 }
 
 inline size_t variantSize(const VariantData* var) {
diff --git a/src/ArduinoJson/Variant/VariantImpl.hpp b/src/ArduinoJson/Variant/VariantImpl.hpp
index 4372949a..fdf5585c 100644
--- a/src/ArduinoJson/Variant/VariantImpl.hpp
+++ b/src/ArduinoJson/Variant/VariantImpl.hpp
@@ -90,8 +90,10 @@ inline bool VariantData::copyFrom(const VariantData& src, MemoryPool* pool) {
     case VALUE_IS_OBJECT:
       return toObject().copyFrom(src._content.asCollection, pool);
     case VALUE_IS_OWNED_STRING: {
-      JsonString value = src.asString();
-      return setString(adaptString(value), pool);
+      auto str = storeString(pool, adaptString(src.asString()),
+                             StringStoragePolicy::Copy());
+      setString(str);
+      return !str.isNull();
     }
     case VALUE_IS_OWNED_RAW:
       return storeOwnedRaw(