diff --git a/src/ArduinoJson.hpp b/src/ArduinoJson.hpp
index a1a01508..8b7e3594 100644
--- a/src/ArduinoJson.hpp
+++ b/src/ArduinoJson.hpp
@@ -9,7 +9,7 @@
 #include "ArduinoJson/deserializeJson.hpp"
 #include "ArduinoJson/deserializeMsgPack.hpp"
 
-#include "ArduinoJson/Json/Serialization/JsonSerializer.hpp"
+#include "ArduinoJson/Json/JsonSerializer.hpp"
 #include "ArduinoJson/JsonArrayImpl.hpp"
 #include "ArduinoJson/JsonObjectImpl.hpp"
 #include "ArduinoJson/JsonVariantImpl.hpp"
diff --git a/src/ArduinoJson/TypeTraits/IsVariant.hpp b/src/ArduinoJson/Data/IsVariant.hpp
similarity index 57%
rename from src/ArduinoJson/TypeTraits/IsVariant.hpp
rename to src/ArduinoJson/Data/IsVariant.hpp
index f8b299f7..2c543417 100644
--- a/src/ArduinoJson/TypeTraits/IsVariant.hpp
+++ b/src/ArduinoJson/Data/IsVariant.hpp
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include "IsBaseOf.hpp"
+#include "../Polyfills/type_traits.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -12,6 +12,6 @@ namespace Internals {
 class JsonVariantTag {};
 
 template <typename T>
-struct IsVariant : IsBaseOf<JsonVariantTag, T> {};
-}
-}
+struct IsVariant : is_base_of<JsonVariantTag, T> {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Data/ValueSaver.hpp b/src/ArduinoJson/Data/ValueSaver.hpp
index 4416ebc9..d3f7e3ae 100644
--- a/src/ArduinoJson/Data/ValueSaver.hpp
+++ b/src/ArduinoJson/Data/ValueSaver.hpp
@@ -6,8 +6,8 @@
 
 #include "../JsonVariant.hpp"
 #include "../Memory/JsonBuffer.hpp"
+#include "../Polyfills/type_traits.hpp"
 #include "../Strings/StringTraits.hpp"
-#include "../TypeTraits/EnableIf.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -23,7 +23,7 @@ struct ValueSaver {
 
 template <typename Source>
 struct ValueSaver<
-    Source, typename EnableIf<StringTraits<Source>::should_duplicate>::type> {
+    Source, typename enable_if<StringTraits<Source>::should_duplicate>::type> {
   template <typename Destination>
   static bool save(JsonBuffer* buffer, Destination& dest, Source source) {
     if (!StringTraits<Source>::is_null(source)) {
@@ -41,7 +41,7 @@ struct ValueSaver<
 // const char*, const signed char*, const unsigned char*
 template <typename Char>
 struct ValueSaver<
-    Char*, typename EnableIf<!StringTraits<Char*>::should_duplicate>::type> {
+    Char*, typename enable_if<!StringTraits<Char*>::should_duplicate>::type> {
   template <typename Destination>
   static bool save(JsonBuffer*, Destination& dest, Char* source) {
     dest = reinterpret_cast<const char*>(source);
diff --git a/src/ArduinoJson/DynamicJsonDocument.hpp b/src/ArduinoJson/DynamicJsonDocument.hpp
index 884c615d..7f88f76c 100644
--- a/src/ArduinoJson/DynamicJsonDocument.hpp
+++ b/src/ArduinoJson/DynamicJsonDocument.hpp
@@ -34,8 +34,8 @@ class DynamicJsonDocument {
 
   // JsonObject& to<JsonObject>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonObject>::value,
-                               JsonObject&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonObject>::value,
+                                JsonObject&>::type
   to() {
     clear();
     JsonObject* object = new (&_buffer) JsonObject(&_buffer);
@@ -46,8 +46,8 @@ class DynamicJsonDocument {
 
   // JsonArray& to<JsonArray>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonArray>::value,
-                               JsonArray&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonArray>::value,
+                                JsonArray&>::type
   to() {
     clear();
     JsonArray* array = new (&_buffer) JsonArray(&_buffer);
@@ -58,8 +58,8 @@ class DynamicJsonDocument {
 
   // JsonVariant& to<JsonVariant>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonVariant>::value,
-                               T&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonVariant>::value,
+                                T&>::type
   to() {
     clear();
     return _root;
diff --git a/src/ArduinoJson/Json/Encoding.hpp b/src/ArduinoJson/Json/EscapeSequence.hpp
similarity index 90%
rename from src/ArduinoJson/Json/Encoding.hpp
rename to src/ArduinoJson/Json/EscapeSequence.hpp
index a0efa2c7..fd3a760c 100644
--- a/src/ArduinoJson/Json/Encoding.hpp
+++ b/src/ArduinoJson/Json/EscapeSequence.hpp
@@ -7,7 +7,7 @@
 namespace ArduinoJson {
 namespace Internals {
 
-class Encoding {
+class EscapeSequence {
  public:
   // Optimized for code size on a 8-bit AVR
   static char escapeChar(char c) {
@@ -33,5 +33,5 @@ class Encoding {
     return &"\"\"\\\\b\bf\fn\nr\rt\t"[excludeIdenticals ? 4 : 0];
   }
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Json/Serialization/IndentedPrint.hpp b/src/ArduinoJson/Json/IndentedPrint.hpp
similarity index 100%
rename from src/ArduinoJson/Json/Serialization/IndentedPrint.hpp
rename to src/ArduinoJson/Json/IndentedPrint.hpp
diff --git a/src/ArduinoJson/Json/Deserialization/JsonDeserializer.hpp b/src/ArduinoJson/Json/JsonDeserializer.hpp
similarity index 95%
rename from src/ArduinoJson/Json/Deserialization/JsonDeserializer.hpp
rename to src/ArduinoJson/Json/JsonDeserializer.hpp
index 3b5d3301..b5457852 100644
--- a/src/ArduinoJson/Json/Deserialization/JsonDeserializer.hpp
+++ b/src/ArduinoJson/Json/JsonDeserializer.hpp
@@ -4,12 +4,12 @@
 
 #pragma once
 
-#include "../../DeserializationError.hpp"
-#include "../../JsonVariant.hpp"
-#include "../../Memory/JsonBuffer.hpp"
-#include "../../Reading/Reader.hpp"
-#include "../../TypeTraits/IsConst.hpp"
-#include "../Encoding.hpp"
+#include "../DeserializationError.hpp"
+#include "../JsonVariant.hpp"
+#include "../Memory/JsonBuffer.hpp"
+#include "../Polyfills/type_traits.hpp"
+#include "../Reading/Reader.hpp"
+#include "./EscapeSequence.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -168,7 +168,8 @@ class JsonDeserializer {
   }
 
   DeserializationError parseString(const char **result) {
-    typename RemoveReference<TWriter>::type::String str = _writer.startString();
+    typename remove_reference<TWriter>::type::String str =
+        _writer.startString();
 
     char c = current();
     if (c == '\0') return DeserializationError::IncompleteInput;
@@ -188,7 +189,7 @@ class JsonDeserializer {
           if (c == '\0') return DeserializationError::IncompleteInput;
           if (c == 'u') return DeserializationError::NotSupported;
           // replace char
-          c = Encoding::unescapeChar(c);
+          c = EscapeSequence::unescapeChar(c);
           if (c == '\0') return DeserializationError::InvalidInput;
           move();
         }
diff --git a/src/ArduinoJson/Json/Serialization/JsonSerializer.hpp b/src/ArduinoJson/Json/JsonSerializer.hpp
similarity index 89%
rename from src/ArduinoJson/Json/Serialization/JsonSerializer.hpp
rename to src/ArduinoJson/Json/JsonSerializer.hpp
index cae6ac84..6bcb0ba8 100644
--- a/src/ArduinoJson/Json/Serialization/JsonSerializer.hpp
+++ b/src/ArduinoJson/Json/JsonSerializer.hpp
@@ -4,15 +4,15 @@
 
 #pragma once
 
-#include "../../Print/DummyPrint.hpp"
-#include "../../Print/DynamicStringBuilder.hpp"
-#include "../../Print/StaticStringBuilder.hpp"
+#include "../Print/DummyPrint.hpp"
+#include "../Print/DynamicStringBuilder.hpp"
+#include "../Print/StaticStringBuilder.hpp"
 #include "./IndentedPrint.hpp"
 #include "./JsonWriter.hpp"
 #include "./Prettyfier.hpp"
 
 #if ARDUINOJSON_ENABLE_STD_STREAM
-#include "../../Print/StreamPrintAdapter.hpp"
+#include "../Print/StreamPrintAdapter.hpp"
 #endif
 
 namespace ArduinoJson {
@@ -96,8 +96,8 @@ class JsonSerializer {
 }  // namespace Internals
 
 template <typename TSource, typename TDestination>
-typename Internals::EnableIf<!Internals::StringTraits<TDestination>::has_append,
-                             size_t>::type
+typename Internals::enable_if<
+    !Internals::StringTraits<TDestination>::has_append, size_t>::type
 serializeJson(const TSource &source, TDestination &destination) {
   Internals::JsonWriter<TDestination> writer(destination);
   Internals::JsonSerializer<Internals::JsonWriter<TDestination> >::serialize(
@@ -126,8 +126,8 @@ size_t serializeJson(const TSource &source, char (&buffer)[N]) {
 }
 
 template <typename TSource, typename TDestination>
-typename Internals::EnableIf<Internals::StringTraits<TDestination>::has_append,
-                             size_t>::type
+typename Internals::enable_if<Internals::StringTraits<TDestination>::has_append,
+                              size_t>::type
 serializeJson(const TSource &source, TDestination &str) {
   Internals::DynamicStringBuilder<TDestination> sb(str);
   return serializeJson(source, sb);
@@ -153,16 +153,16 @@ size_t serializeJsonPretty(const TSource &source, char (&buffer)[N]) {
 }
 
 template <typename TSource, typename TDestination>
-typename Internals::EnableIf<!Internals::StringTraits<TDestination>::has_append,
-                             size_t>::type
+typename Internals::enable_if<
+    !Internals::StringTraits<TDestination>::has_append, size_t>::type
 serializeJsonPretty(const TSource &source, TDestination &print) {
   Internals::IndentedPrint<TDestination> indentedPrint(print);
   return serializeJsonPretty(source, indentedPrint);
 }
 
 template <typename TSource, typename TDestination>
-typename Internals::EnableIf<Internals::StringTraits<TDestination>::has_append,
-                             size_t>::type
+typename Internals::enable_if<Internals::StringTraits<TDestination>::has_append,
+                              size_t>::type
 serializeJsonPretty(const TSource &source, TDestination &str) {
   Internals::DynamicStringBuilder<TDestination> sb(str);
   return serializeJsonPretty(source, sb);
diff --git a/src/ArduinoJson/Json/Serialization/JsonWriter.hpp b/src/ArduinoJson/Json/JsonWriter.hpp
similarity index 90%
rename from src/ArduinoJson/Json/Serialization/JsonWriter.hpp
rename to src/ArduinoJson/Json/JsonWriter.hpp
index f613f7e5..93d7694c 100644
--- a/src/ArduinoJson/Json/Serialization/JsonWriter.hpp
+++ b/src/ArduinoJson/Json/JsonWriter.hpp
@@ -5,10 +5,10 @@
 #pragma once
 
 #include <stdint.h>
-#include "../../Data/JsonInteger.hpp"
-#include "../../Polyfills/attributes.hpp"
-#include "../Encoding.hpp"
-#include "./FloatParts.hpp"
+#include "../Data/JsonInteger.hpp"
+#include "../Numbers/FloatParts.hpp"
+#include "../Polyfills/attributes.hpp"
+#include "./EscapeSequence.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -66,7 +66,7 @@ class JsonWriter {
   }
 
   void writeChar(char c) {
-    char specialChar = Encoding::escapeChar(c);
+    char specialChar = EscapeSequence::escapeChar(c);
     if (specialChar) {
       writeRaw('\\');
       writeRaw(specialChar);
@@ -77,14 +77,14 @@ class JsonWriter {
 
   template <typename TFloat>
   void writeFloat(TFloat value) {
-    if (isNaN(value)) return writeRaw("NaN");
+    if (isnan(value)) return writeRaw("NaN");
 
     if (value < 0.0) {
       writeRaw('-');
       value = -value;
     }
 
-    if (isInfinity(value)) return writeRaw("Infinity");
+    if (isinf(value)) return writeRaw("Infinity");
 
     FloatParts<TFloat> parts(value);
 
diff --git a/src/ArduinoJson/Json/Serialization/Prettyfier.hpp b/src/ArduinoJson/Json/Prettyfier.hpp
similarity index 100%
rename from src/ArduinoJson/Json/Serialization/Prettyfier.hpp
rename to src/ArduinoJson/Json/Prettyfier.hpp
diff --git a/src/ArduinoJson/JsonArray.hpp b/src/ArduinoJson/JsonArray.hpp
index d52430fd..d174c621 100644
--- a/src/ArduinoJson/JsonArray.hpp
+++ b/src/ArduinoJson/JsonArray.hpp
@@ -9,11 +9,8 @@
 #include "Data/ValueSaver.hpp"
 #include "JsonVariant.hpp"
 #include "Memory/JsonBufferAllocated.hpp"
+#include "Polyfills/type_traits.hpp"
 #include "Strings/StringTraits.hpp"
-#include "TypeTraits/EnableIf.hpp"
-#include "TypeTraits/IsArray.hpp"
-#include "TypeTraits/IsFloatingPoint.hpp"
-#include "TypeTraits/IsSame.hpp"
 
 // Returns the size (in bytes) of an array with n elements.
 // Can be very handy to determine the size of a StaticJsonBuffer.
@@ -88,7 +85,8 @@ class JsonArray : public Internals::ReferenceType,
   // bool set(size_t index, TValue value, uint8_t decimals);
   // TValue = float, double
   template <typename T>
-  typename Internals::EnableIf<Internals::IsFloatingPoint<T>::value, bool>::type
+  typename Internals::enable_if<Internals::is_floating_point<T>::value,
+                                bool>::type
   set(size_t index, T value, uint8_t decimals) {
     return set_impl<const JsonVariant &>(index, JsonVariant(value, decimals));
   }
diff --git a/src/ArduinoJson/JsonObject.hpp b/src/ArduinoJson/JsonObject.hpp
index def89b95..22c8af8e 100644
--- a/src/ArduinoJson/JsonObject.hpp
+++ b/src/ArduinoJson/JsonObject.hpp
@@ -9,11 +9,8 @@
 #include "Data/ValueSaver.hpp"
 #include "JsonPair.hpp"
 #include "Memory/JsonBufferAllocated.hpp"
+#include "Polyfills/type_traits.hpp"
 #include "Strings/StringTraits.hpp"
-#include "TypeTraits/EnableIf.hpp"
-#include "TypeTraits/IsArray.hpp"
-#include "TypeTraits/IsFloatingPoint.hpp"
-#include "TypeTraits/IsSame.hpp"
 
 // Returns the size (in bytes) of an object with n elements.
 // Can be very handy to determine the size of a StaticJsonBuffer.
diff --git a/src/ArduinoJson/JsonObjectSubscript.hpp b/src/ArduinoJson/JsonObjectSubscript.hpp
index f323fb32..9d11ac20 100644
--- a/src/ArduinoJson/JsonObjectSubscript.hpp
+++ b/src/ArduinoJson/JsonObjectSubscript.hpp
@@ -6,7 +6,7 @@
 
 #include "Configuration.hpp"
 #include "JsonVariantBase.hpp"
-#include "TypeTraits/EnableIf.hpp"
+#include "Polyfills/type_traits.hpp"
 
 #ifdef _MSC_VER
 #pragma warning(push)
@@ -36,7 +36,7 @@ class JsonObjectSubscript
   // TValue = bool, char, long, int, short, float, double,
   //          std::string, String, JsonArray, JsonObject
   template <typename TValue>
-  FORCE_INLINE typename EnableIf<!IsArray<TValue>::value, this_type&>::type
+  FORCE_INLINE typename enable_if<!is_array<TValue>::value, this_type&>::type
   operator=(const TValue& src) {
     _object.set(_key, src);
     return *this;
@@ -70,7 +70,7 @@ class JsonObjectSubscript
   // TValue = bool, char, long, int, short, float, double, RawJson, JsonVariant,
   //          std::string, String, JsonArray, JsonObject
   template <typename TValue>
-  FORCE_INLINE typename EnableIf<!IsArray<TValue>::value, bool>::type set(
+  FORCE_INLINE typename enable_if<!is_array<TValue>::value, bool>::type set(
       const TValue& value) {
     return _object.set(_key, value);
   }
diff --git a/src/ArduinoJson/JsonVariant.hpp b/src/ArduinoJson/JsonVariant.hpp
index 1a79af06..a4ad82ee 100644
--- a/src/ArduinoJson/JsonVariant.hpp
+++ b/src/ArduinoJson/JsonVariant.hpp
@@ -11,16 +11,8 @@
 #include "Data/JsonVariantDefault.hpp"
 #include "Data/JsonVariantType.hpp"
 #include "JsonVariantBase.hpp"
+#include "Polyfills/type_traits.hpp"
 #include "RawJson.hpp"
-#include "TypeTraits/EnableIf.hpp"
-#include "TypeTraits/IsChar.hpp"
-#include "TypeTraits/IsFloatingPoint.hpp"
-#include "TypeTraits/IsIntegral.hpp"
-#include "TypeTraits/IsSame.hpp"
-#include "TypeTraits/IsSignedIntegral.hpp"
-#include "TypeTraits/IsUnsignedIntegral.hpp"
-#include "TypeTraits/RemoveConst.hpp"
-#include "TypeTraits/RemoveReference.hpp"
 
 namespace ArduinoJson {
 
@@ -52,8 +44,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonVariant(double value);
   // JsonVariant(float value);
   template <typename T>
-  JsonVariant(T value, typename Internals::EnableIf<
-                           Internals::IsFloatingPoint<T>::value>::type * = 0) {
+  JsonVariant(T value,
+              typename Internals::enable_if<
+                  Internals::is_floating_point<T>::value>::type * = 0) {
     using namespace Internals;
     _type = JSON_FLOAT;
     _content.asFloat = static_cast<JsonFloat>(value);
@@ -68,8 +61,8 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   template <typename T>
   JsonVariant(
       T value,
-      typename Internals::EnableIf<Internals::IsSignedIntegral<T>::value ||
-                                   Internals::IsSame<T, char>::value>::type * =
+      typename Internals::enable_if<Internals::is_integral<T>::value &&
+                                    Internals::is_signed<T>::value>::type * =
           0) {
     using namespace Internals;
     if (value >= 0) {
@@ -84,9 +77,11 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonVariant(unsigned int)
   // JsonVariant(unsigned long)
   template <typename T>
-  JsonVariant(T value,
-              typename Internals::EnableIf<
-                  Internals::IsUnsignedIntegral<T>::value>::type * = 0) {
+  JsonVariant(
+      T value,
+      typename Internals::enable_if<Internals::is_integral<T>::value &&
+                                    Internals::is_unsigned<T>::value>::type * =
+          0) {
     using namespace Internals;
     _type = JSON_POSITIVE_INTEGER;
     _content.asInteger = static_cast<JsonUInt>(value);
@@ -97,10 +92,8 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonVariant(const signed char*);
   // JsonVariant(const unsigned char*);
   template <typename TChar>
-  JsonVariant(
-      const TChar *value,
-      typename Internals::EnableIf<Internals::IsChar<TChar>::value>::type * =
-          0) {
+  JsonVariant(const TChar *value,
+              typename Internals::enable_if<sizeof(TChar) == 1>::type * = 0) {
     _type = Internals::JSON_STRING;
     _content.asString = reinterpret_cast<const char *>(value);
   }
@@ -143,13 +136,14 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // unsigned int as<unsigned int>() const;
   // unsigned long as<unsigned long>() const;
   template <typename T>
-  const typename Internals::EnableIf<Internals::IsIntegral<T>::value, T>::type
+  const typename Internals::enable_if<Internals::is_integral<T>::value, T>::type
   as() const {
     return variantAsInteger<T>();
   }
   // bool as<bool>() const
   template <typename T>
-  const typename Internals::EnableIf<Internals::IsSame<T, bool>::value, T>::type
+  const typename Internals::enable_if<Internals::is_same<T, bool>::value,
+                                      T>::type
   as() const {
     return variantAsInteger<int>() != 0;
   }
@@ -157,8 +151,8 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // double as<double>() const;
   // float as<float>() const;
   template <typename T>
-  const typename Internals::EnableIf<Internals::IsFloatingPoint<T>::value,
-                                     T>::type
+  const typename Internals::enable_if<Internals::is_floating_point<T>::value,
+                                      T>::type
   as() const {
     return variantAsFloat<T>();
   }
@@ -166,9 +160,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // const char* as<const char*>() const;
   // const char* as<char*>() const;
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, const char *>::value ||
-                                   Internals::IsSame<T, char *>::value,
-                               const char *>::type
+  typename Internals::enable_if<Internals::is_same<T, const char *>::value ||
+                                    Internals::is_same<T, char *>::value,
+                                const char *>::type
   as() const {
     return variantAsString();
   }
@@ -176,7 +170,7 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // std::string as<std::string>() const;
   // String as<String>() const;
   template <typename T>
-  typename Internals::EnableIf<Internals::StringTraits<T>::has_append, T>::type
+  typename Internals::enable_if<Internals::StringTraits<T>::has_append, T>::type
   as() const {
     const char *cstr = variantAsString();
     if (cstr) return T(cstr);
@@ -188,9 +182,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonArray& as<JsonArray> const;
   // JsonArray& as<JsonArray&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveReference<T>::type,
-                        JsonArray>::value,
+  typename Internals::enable_if<
+      Internals::is_same<typename Internals::remove_reference<T>::type,
+                         JsonArray>::value,
       JsonArray &>::type
   as() const {
     return variantAsArray();
@@ -198,9 +192,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   //
   // const JsonArray& as<const JsonArray&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveReference<T>::type,
-                        const JsonArray>::value,
+  typename Internals::enable_if<
+      Internals::is_same<typename Internals::remove_reference<T>::type,
+                         const JsonArray>::value,
       const JsonArray &>::type
   as() const {
     return variantAsArray();
@@ -209,9 +203,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonObject& as<JsonObject> const;
   // JsonObject& as<JsonObject&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveReference<T>::type,
-                        JsonObject>::value,
+  typename Internals::enable_if<
+      Internals::is_same<typename Internals::remove_reference<T>::type,
+                         JsonObject>::value,
       JsonObject &>::type
   as() const {
     return variantAsObject();
@@ -220,9 +214,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // JsonObject& as<const JsonObject> const;
   // JsonObject& as<const JsonObject&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveReference<T>::type,
-                        const JsonObject>::value,
+  typename Internals::enable_if<
+      Internals::is_same<typename Internals::remove_reference<T>::type,
+                         const JsonObject>::value,
       const JsonObject &>::type
   as() const {
     return variantAsObject();
@@ -230,8 +224,8 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   //
   // JsonVariant as<JsonVariant> const;
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonVariant>::value,
-                               T>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonVariant>::value,
+                                T>::type
   as() const {
     return *this;
   }
@@ -249,22 +243,23 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // bool is<unsigned int>() const;
   // bool is<unsigned long>() const;
   template <typename T>
-  typename Internals::EnableIf<Internals::IsIntegral<T>::value, bool>::type is()
-      const {
+  typename Internals::enable_if<Internals::is_integral<T>::value, bool>::type
+  is() const {
     return variantIsInteger();
   }
   //
   // bool is<double>() const;
   // bool is<float>() const;
   template <typename T>
-  typename Internals::EnableIf<Internals::IsFloatingPoint<T>::value, bool>::type
+  typename Internals::enable_if<Internals::is_floating_point<T>::value,
+                                bool>::type
   is() const {
     return variantIsFloat();
   }
   //
   // bool is<bool>() const
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, bool>::value, bool>::type
+  typename Internals::enable_if<Internals::is_same<T, bool>::value, bool>::type
   is() const {
     return variantIsBoolean();
   }
@@ -272,9 +267,9 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // bool is<const char*>() const;
   // bool is<char*>() const;
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, const char *>::value ||
-                                   Internals::IsSame<T, char *>::value,
-                               bool>::type
+  typename Internals::enable_if<Internals::is_same<T, const char *>::value ||
+                                    Internals::is_same<T, char *>::value,
+                                bool>::type
   is() const {
     return variantIsString();
   }
@@ -283,10 +278,11 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // bool is<JsonArray&> const;
   // bool is<const JsonArray&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveConst<
-                            typename Internals::RemoveReference<T>::type>::type,
-                        JsonArray>::value,
+  typename Internals::enable_if<
+      Internals::is_same<
+          typename Internals::remove_const<
+              typename Internals::remove_reference<T>::type>::type,
+          JsonArray>::value,
       bool>::type
   is() const {
     return variantIsArray();
@@ -296,10 +292,11 @@ class JsonVariant : public Internals::JsonVariantBase<JsonVariant> {
   // bool is<JsonObject&> const;
   // bool is<const JsonObject&> const;
   template <typename T>
-  typename Internals::EnableIf<
-      Internals::IsSame<typename Internals::RemoveConst<
-                            typename Internals::RemoveReference<T>::type>::type,
-                        JsonObject>::value,
+  typename Internals::enable_if<
+      Internals::is_same<
+          typename Internals::remove_const<
+              typename Internals::remove_reference<T>::type>::type,
+          JsonObject>::value,
       bool>::type
   is() const {
     return variantIsObject();
diff --git a/src/ArduinoJson/JsonVariantComparisons.hpp b/src/ArduinoJson/JsonVariantComparisons.hpp
index dbd84d97..39317a67 100644
--- a/src/ArduinoJson/JsonVariantComparisons.hpp
+++ b/src/ArduinoJson/JsonVariantComparisons.hpp
@@ -4,9 +4,9 @@
 
 #pragma once
 
+#include "Data/IsVariant.hpp"
+#include "Polyfills/type_traits.hpp"
 #include "Strings/StringTraits.hpp"
-#include "TypeTraits/EnableIf.hpp"
-#include "TypeTraits/IsVariant.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -21,7 +21,7 @@ class JsonVariantComparisons {
   }
 
   template <typename TComparand>
-  friend typename EnableIf<!IsVariant<TComparand>::value, bool>::type
+  friend typename enable_if<!IsVariant<TComparand>::value, bool>::type
   operator==(TComparand comparand, const JsonVariantComparisons &variant) {
     return variant.equals(comparand);
   }
@@ -33,7 +33,7 @@ class JsonVariantComparisons {
   }
 
   template <typename TComparand>
-  friend typename EnableIf<!IsVariant<TComparand>::value, bool>::type
+  friend typename enable_if<!IsVariant<TComparand>::value, bool>::type
   operator!=(TComparand comparand, const JsonVariantComparisons &variant) {
     return !variant.equals(comparand);
   }
@@ -101,16 +101,16 @@ class JsonVariantComparisons {
   }
 
   template <typename TString>
-  typename EnableIf<StringTraits<TString>::has_equals, bool>::type equals(
+  typename enable_if<StringTraits<TString>::has_equals, bool>::type equals(
       const TString &comparand) const {
     const char *value = as<const char *>();
     return StringTraits<TString>::equals(comparand, value);
   }
 
   template <typename TComparand>
-  typename EnableIf<!IsVariant<TComparand>::value &&
-                        !StringTraits<TComparand>::has_equals,
-                    bool>::type
+  typename enable_if<!IsVariant<TComparand>::value &&
+                         !StringTraits<TComparand>::has_equals,
+                     bool>::type
   equals(const TComparand &comparand) const {
     return as<TComparand>() == comparand;
   }
diff --git a/src/ArduinoJson/JsonVariantImpl.hpp b/src/ArduinoJson/JsonVariantImpl.hpp
index 138827cb..d7ffec08 100644
--- a/src/ArduinoJson/JsonVariantImpl.hpp
+++ b/src/ArduinoJson/JsonVariantImpl.hpp
@@ -8,10 +8,10 @@
 #include "JsonArray.hpp"
 #include "JsonObject.hpp"
 #include "JsonVariant.hpp"
-#include "Text/isFloat.hpp"
-#include "Text/isInteger.hpp"
-#include "Text/parseFloat.hpp"
-#include "Text/parseInteger.hpp"
+#include "Numbers/isFloat.hpp"
+#include "Numbers/isInteger.hpp"
+#include "Numbers/parseFloat.hpp"
+#include "Numbers/parseInteger.hpp"
 
 #include <string.h>  // for strcmp
 
diff --git a/src/ArduinoJson/JsonVariantOr.hpp b/src/ArduinoJson/JsonVariantOr.hpp
index d8022fcb..912831f7 100644
--- a/src/ArduinoJson/JsonVariantOr.hpp
+++ b/src/ArduinoJson/JsonVariantOr.hpp
@@ -6,8 +6,7 @@
 
 #include "Data/JsonVariantAs.hpp"
 #include "Polyfills/attributes.hpp"
-#include "TypeTraits/EnableIf.hpp"
-#include "TypeTraits/IsIntegral.hpp"
+#include "Polyfills/type_traits.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -17,7 +16,7 @@ class JsonVariantOr {
  public:
   // Returns the default value if the JsonVariant is undefined of incompatible
   template <typename T>
-  typename EnableIf<!IsIntegral<T>::value, T>::type operator|(
+  typename enable_if<!is_integral<T>::value, T>::type operator|(
       const T &defaultValue) const {
     if (impl()->template is<T>())
       return impl()->template as<T>();
@@ -35,7 +34,7 @@ class JsonVariantOr {
   // Returns the default value if the JsonVariant is undefined of incompatible
   // Special case for integers: we also accept double
   template <typename Integer>
-  typename EnableIf<IsIntegral<Integer>::value, Integer>::type operator|(
+  typename enable_if<is_integral<Integer>::value, Integer>::type operator|(
       const Integer &defaultValue) const {
     if (impl()->template is<double>())
       return impl()->template as<Integer>();
diff --git a/src/ArduinoJson/JsonVariantSubscripts.hpp b/src/ArduinoJson/JsonVariantSubscripts.hpp
index ec28c686..d75ec052 100644
--- a/src/ArduinoJson/JsonVariantSubscripts.hpp
+++ b/src/ArduinoJson/JsonVariantSubscripts.hpp
@@ -6,8 +6,8 @@
 
 #include "Data/JsonVariantAs.hpp"
 #include "Polyfills/attributes.hpp"
+#include "Polyfills/type_traits.hpp"
 #include "Strings/StringTraits.hpp"
-#include "TypeTraits/EnableIf.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -43,8 +43,8 @@ class JsonVariantSubscripts {
   // TKey = const std::string&, const String&
   template <typename TString>
   FORCE_INLINE
-      typename EnableIf<StringTraits<TString>::has_equals,
-                        const JsonObjectSubscript<const TString &> >::type
+      typename enable_if<StringTraits<TString>::has_equals,
+                         const JsonObjectSubscript<const TString &> >::type
       operator[](const TString &key) const {
     return impl()->template as<JsonObject>()[key];
   }
@@ -52,8 +52,8 @@ class JsonVariantSubscripts {
   // const JsonObjectSubscript operator[](TKey) const;
   // TKey = const std::string&, const String&
   template <typename TString>
-  FORCE_INLINE typename EnableIf<StringTraits<TString>::has_equals,
-                                 JsonObjectSubscript<const TString &> >::type
+  FORCE_INLINE typename enable_if<StringTraits<TString>::has_equals,
+                                  JsonObjectSubscript<const TString &> >::type
   operator[](const TString &key) {
     return impl()->template as<JsonObject>()[key];
   }
@@ -61,8 +61,8 @@ class JsonVariantSubscripts {
   // JsonObjectSubscript operator[](TKey);
   // TKey = const char*, const char[N], const FlashStringHelper*
   template <typename TString>
-  FORCE_INLINE typename EnableIf<StringTraits<const TString *>::has_equals,
-                                 JsonObjectSubscript<const TString *> >::type
+  FORCE_INLINE typename enable_if<StringTraits<const TString *>::has_equals,
+                                  JsonObjectSubscript<const TString *> >::type
   operator[](const TString *key) {
     return impl()->template as<JsonObject>()[key];
   }
@@ -71,8 +71,8 @@ class JsonVariantSubscripts {
   // TKey = const char*, const char[N], const FlashStringHelper*
   template <typename TString>
   FORCE_INLINE
-      typename EnableIf<StringTraits<TString *>::has_equals,
-                        const JsonObjectSubscript<const TString *> >::type
+      typename enable_if<StringTraits<TString *>::has_equals,
+                         const JsonObjectSubscript<const TString *> >::type
       operator[](const TString *key) const {
     return impl()->template as<JsonObject>()[key];
   }
diff --git a/src/ArduinoJson/Memory/StaticJsonBuffer.hpp b/src/ArduinoJson/Memory/StaticJsonBuffer.hpp
index eb4fc36e..71d6ddbc 100644
--- a/src/ArduinoJson/Memory/StaticJsonBuffer.hpp
+++ b/src/ArduinoJson/Memory/StaticJsonBuffer.hpp
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include "../TypeTraits/Max.hpp"
+#include "../Polyfills/mpl/max.hpp"
 #include "JsonBuffer.hpp"
 
 namespace ArduinoJson {
diff --git a/src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp b/src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp
index 34dc11de..c043eca3 100644
--- a/src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp
+++ b/src/ArduinoJson/MsgPack/MsgPackDeserializer.hpp
@@ -7,8 +7,8 @@
 #include "../DeserializationError.hpp"
 #include "../JsonVariant.hpp"
 #include "../Memory/JsonBuffer.hpp"
+#include "../Polyfills/type_traits.hpp"
 #include "../Reading/Reader.hpp"
-#include "../TypeTraits/IsConst.hpp"
 #include "../Writing/Writer.hpp"
 #include "./endianess.hpp"
 #include "./ieee754.hpp"
@@ -181,7 +181,7 @@ class MsgPackDeserializer {
   }
 
   template <typename T>
-  typename EnableIf<sizeof(T) == 4, DeserializationError>::type readFloat(
+  typename enable_if<sizeof(T) == 4, DeserializationError>::type readFloat(
       JsonVariant &variant) {
     T value;
     if (!readBytes(value)) return DeserializationError::IncompleteInput;
@@ -191,7 +191,7 @@ class MsgPackDeserializer {
   }
 
   template <typename T>
-  typename EnableIf<sizeof(T) == 8, DeserializationError>::type readDouble(
+  typename enable_if<sizeof(T) == 8, DeserializationError>::type readDouble(
       JsonVariant &variant) {
     T value;
     if (!readBytes(value)) return DeserializationError::IncompleteInput;
@@ -201,7 +201,7 @@ class MsgPackDeserializer {
   }
 
   template <typename T>
-  typename EnableIf<sizeof(T) == 4, DeserializationError>::type readDouble(
+  typename enable_if<sizeof(T) == 4, DeserializationError>::type readDouble(
       JsonVariant &variant) {
     uint8_t i[8];  // input is 8 bytes
     T value;       // output is 4 bytes
@@ -221,7 +221,8 @@ class MsgPackDeserializer {
   }
 
   DeserializationError readString(JsonVariant &variant, size_t n) {
-    typename RemoveReference<TWriter>::type::String str = _writer.startString();
+    typename remove_reference<TWriter>::type::String str =
+        _writer.startString();
     for (; n; --n) {
       uint8_t c;
       if (!readBytes(c)) return DeserializationError::IncompleteInput;
diff --git a/src/ArduinoJson/MsgPack/endianess.hpp b/src/ArduinoJson/MsgPack/endianess.hpp
index 26f2b906..aa6bb837 100644
--- a/src/ArduinoJson/MsgPack/endianess.hpp
+++ b/src/ArduinoJson/MsgPack/endianess.hpp
@@ -4,12 +4,11 @@
 
 #pragma once
 
+#include "../Polyfills/type_traits.hpp"
+
 namespace ArduinoJson {
 namespace Internals {
 
-template <class T, T v>
-struct integral_constant {};
-
 template <typename T>
 inline void swap(T& a, T& b) {
   T t(a);
diff --git a/src/ArduinoJson/Json/Serialization/FloatParts.hpp b/src/ArduinoJson/Numbers/FloatParts.hpp
similarity index 95%
rename from src/ArduinoJson/Json/Serialization/FloatParts.hpp
rename to src/ArduinoJson/Numbers/FloatParts.hpp
index 4f42a9c2..d7c34274 100644
--- a/src/ArduinoJson/Json/Serialization/FloatParts.hpp
+++ b/src/ArduinoJson/Numbers/FloatParts.hpp
@@ -4,9 +4,9 @@
 
 #pragma once
 
-#include "../../Configuration.hpp"
-#include "../../Polyfills/math.hpp"
-#include "../../TypeTraits/FloatTraits.hpp"
+#include "../Configuration.hpp"
+#include "../Polyfills/math.hpp"
+#include "./FloatTraits.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
diff --git a/src/ArduinoJson/TypeTraits/FloatTraits.hpp b/src/ArduinoJson/Numbers/FloatTraits.hpp
similarity index 98%
rename from src/ArduinoJson/TypeTraits/FloatTraits.hpp
rename to src/ArduinoJson/Numbers/FloatTraits.hpp
index 5044807a..a6ebcc12 100644
--- a/src/ArduinoJson/TypeTraits/FloatTraits.hpp
+++ b/src/ArduinoJson/Numbers/FloatTraits.hpp
@@ -146,5 +146,5 @@ struct FloatTraits<T, 4 /*32bits*/> {
     return forge(0x7f800000);
   }
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Text/isFloat.hpp b/src/ArduinoJson/Numbers/isFloat.hpp
similarity index 100%
rename from src/ArduinoJson/Text/isFloat.hpp
rename to src/ArduinoJson/Numbers/isFloat.hpp
diff --git a/src/ArduinoJson/Text/isInteger.hpp b/src/ArduinoJson/Numbers/isInteger.hpp
similarity index 100%
rename from src/ArduinoJson/Text/isInteger.hpp
rename to src/ArduinoJson/Numbers/isInteger.hpp
diff --git a/src/ArduinoJson/Text/parseFloat.hpp b/src/ArduinoJson/Numbers/parseFloat.hpp
similarity index 97%
rename from src/ArduinoJson/Text/parseFloat.hpp
rename to src/ArduinoJson/Numbers/parseFloat.hpp
index 763ab3d8..e50f9059 100644
--- a/src/ArduinoJson/Text/parseFloat.hpp
+++ b/src/ArduinoJson/Numbers/parseFloat.hpp
@@ -4,9 +4,9 @@
 
 #pragma once
 
+#include "../Numbers/FloatTraits.hpp"
 #include "../Polyfills/ctype.hpp"
 #include "../Polyfills/math.hpp"
-#include "../TypeTraits/FloatTraits.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
diff --git a/src/ArduinoJson/Text/parseInteger.hpp b/src/ArduinoJson/Numbers/parseInteger.hpp
similarity index 100%
rename from src/ArduinoJson/Text/parseInteger.hpp
rename to src/ArduinoJson/Numbers/parseInteger.hpp
diff --git a/src/ArduinoJson/Polyfills/math.hpp b/src/ArduinoJson/Polyfills/math.hpp
index 48773edd..32417c0c 100644
--- a/src/ArduinoJson/Polyfills/math.hpp
+++ b/src/ArduinoJson/Polyfills/math.hpp
@@ -7,13 +7,13 @@
 namespace ArduinoJson {
 namespace Internals {
 template <typename T>
-bool isNaN(T x) {
+bool isnan(T x) {
   return x != x;
 }
 
 template <typename T>
-bool isInfinity(T x) {
+bool isinf(T x) {
   return x != 0.0 && x * 2 == x;
 }
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/Max.hpp b/src/ArduinoJson/Polyfills/mpl/max.hpp
similarity index 100%
rename from src/ArduinoJson/TypeTraits/Max.hpp
rename to src/ArduinoJson/Polyfills/mpl/max.hpp
diff --git a/src/ArduinoJson/Polyfills/type_traits.hpp b/src/ArduinoJson/Polyfills/type_traits.hpp
new file mode 100644
index 00000000..fa5b9e50
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits.hpp
@@ -0,0 +1,18 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "type_traits/enable_if.hpp"
+#include "type_traits/integral_constant.hpp"
+#include "type_traits/is_array.hpp"
+#include "type_traits/is_base_of.hpp"
+#include "type_traits/is_const.hpp"
+#include "type_traits/is_floating_point.hpp"
+#include "type_traits/is_integral.hpp"
+#include "type_traits/is_same.hpp"
+#include "type_traits/is_signed.hpp"
+#include "type_traits/is_unsigned.hpp"
+#include "type_traits/remove_const.hpp"
+#include "type_traits/remove_reference.hpp"
diff --git a/src/ArduinoJson/TypeTraits/EnableIf.hpp b/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
similarity index 74%
rename from src/ArduinoJson/TypeTraits/EnableIf.hpp
rename to src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
index 83fc5e07..70dd92e6 100644
--- a/src/ArduinoJson/TypeTraits/EnableIf.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/enable_if.hpp
@@ -9,11 +9,11 @@ namespace Internals {
 
 // A meta-function that return the type T if Condition is true.
 template <bool Condition, typename T = void>
-struct EnableIf {};
+struct enable_if {};
 
 template <typename T>
-struct EnableIf<true, T> {
+struct enable_if<true, T> {
   typedef T type;
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp b/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp
new file mode 100644
index 00000000..7ce931c3
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/integral_constant.hpp
@@ -0,0 +1,19 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename T, T v>
+struct integral_constant {
+  static const T value = v;
+};
+
+typedef integral_constant<bool, true> true_type;
+typedef integral_constant<bool, false> false_type;
+
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_array.hpp b/src/ArduinoJson/Polyfills/type_traits/is_array.hpp
new file mode 100644
index 00000000..17075d4a
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/is_array.hpp
@@ -0,0 +1,19 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename T>
+struct is_array : false_type {};
+
+template <typename T>
+struct is_array<T[]> : true_type {};
+
+template <typename T, size_t N>
+struct is_array<T[N]> : true_type {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/IsBaseOf.hpp b/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
similarity index 88%
rename from src/ArduinoJson/TypeTraits/IsBaseOf.hpp
rename to src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
index bf24e965..be6ddeac 100644
--- a/src/ArduinoJson/TypeTraits/IsBaseOf.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_base_of.hpp
@@ -10,7 +10,7 @@ namespace Internals {
 // A meta-function that returns true if Derived inherits from TBase is an
 // integral type.
 template <typename TBase, typename TDerived>
-class IsBaseOf {
+class is_base_of {
  protected:  // <- to avoid GCC's "all member functions in class are private"
   typedef char Yes[1];
   typedef char No[2];
@@ -23,5 +23,5 @@ class IsBaseOf {
     value = sizeof(probe(reinterpret_cast<TDerived *>(0))) == sizeof(Yes)
   };
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/IsConst.hpp b/src/ArduinoJson/Polyfills/type_traits/is_const.hpp
similarity index 61%
rename from src/ArduinoJson/TypeTraits/IsConst.hpp
rename to src/ArduinoJson/Polyfills/type_traits/is_const.hpp
index 512ee5ca..0a2dfda9 100644
--- a/src/ArduinoJson/TypeTraits/IsConst.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_const.hpp
@@ -4,18 +4,16 @@
 
 #pragma once
 
+#include "integral_constant.hpp"
+
 namespace ArduinoJson {
 namespace Internals {
 
 // A meta-function that return the type T without the const modifier
 template <typename T>
-struct IsConst {
-  static const bool value = false;
-};
+struct is_const : false_type {};
 
 template <typename T>
-struct IsConst<const T> {
-  static const bool value = true;
-};
-}
-}
+struct is_const<const T> : true_type {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_floating_point.hpp b/src/ArduinoJson/Polyfills/type_traits/is_floating_point.hpp
new file mode 100644
index 00000000..24e74ab7
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/is_floating_point.hpp
@@ -0,0 +1,21 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "integral_constant.hpp"
+
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename>
+struct is_floating_point : false_type {};
+
+template <>
+struct is_floating_point<float> : true_type {};
+
+template <>
+struct is_floating_point<double> : true_type {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp b/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp
new file mode 100644
index 00000000..e97a09cc
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/is_integral.hpp
@@ -0,0 +1,35 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "is_same.hpp"
+
+namespace ArduinoJson {
+namespace Internals {
+
+// A meta-function that returns true if T is an integral type.
+template <typename T>
+struct is_integral {
+  static const bool value =
+      is_same<T, signed char>::value || is_same<T, unsigned char>::value ||
+      is_same<T, signed short>::value || is_same<T, unsigned short>::value ||
+      is_same<T, signed int>::value || is_same<T, unsigned int>::value ||
+      is_same<T, signed long>::value || is_same<T, unsigned long>::value ||
+#if ARDUINOJSON_USE_LONG_LONG
+      is_same<T, unsigned long long>::value ||
+      is_same<T, signed long long>::value ||
+#endif
+#if ARDUINOJSON_USE_INT64
+      is_same<T, unsigned __int64>::value ||
+      is_same<T, signed __int64>::value ||
+#endif
+      is_same<T, char>::value;
+  // CAUTION: differs from std::is_integral as it doesn't include bool
+};
+
+template <typename T>
+struct is_integral<const T> : is_integral<T> {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/IsSame.hpp b/src/ArduinoJson/Polyfills/type_traits/is_same.hpp
similarity index 63%
rename from src/ArduinoJson/TypeTraits/IsSame.hpp
rename to src/ArduinoJson/Polyfills/type_traits/is_same.hpp
index 06567c93..920f5b54 100644
--- a/src/ArduinoJson/TypeTraits/IsSame.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/is_same.hpp
@@ -4,18 +4,16 @@
 
 #pragma once
 
+#include "integral_constant.hpp"
+
 namespace ArduinoJson {
 namespace Internals {
 
 // A meta-function that returns true if types T and U are the same.
 template <typename T, typename U>
-struct IsSame {
-  static const bool value = false;
-};
+struct is_same : false_type {};
 
 template <typename T>
-struct IsSame<T, T> {
-  static const bool value = true;
-};
-}
-}
+struct is_same<T, T> : true_type {};
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp b/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp
new file mode 100644
index 00000000..b145c5ea
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/is_signed.hpp
@@ -0,0 +1,44 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "integral_constant.hpp"
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename>
+struct is_signed : false_type {};
+
+template <>
+struct is_signed<char> : true_type {};
+
+template <>
+struct is_signed<signed char> : true_type {};
+
+template <>
+struct is_signed<signed short> : true_type {};
+
+template <>
+struct is_signed<signed int> : true_type {};
+
+template <>
+struct is_signed<signed long> : true_type {};
+
+template <>
+struct is_signed<float> : true_type {};
+
+template <>
+struct is_signed<double> : true_type {};
+
+#if ARDUINOJSON_USE_LONG_LONG
+template <>
+struct is_signed<signed long long> : true_type {};
+#endif
+#if ARDUINOJSON_USE_INT64
+template <>
+struct is_signed<signed __int64> : true_type {};
+#endif
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp b/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp
new file mode 100644
index 00000000..4de418d0
--- /dev/null
+++ b/src/ArduinoJson/Polyfills/type_traits/is_unsigned.hpp
@@ -0,0 +1,38 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include "integral_constant.hpp"
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename>
+struct is_unsigned : false_type {};
+
+template <>
+struct is_unsigned<bool> : true_type {};
+
+template <>
+struct is_unsigned<unsigned char> : true_type {};
+
+template <>
+struct is_unsigned<unsigned short> : true_type {};
+
+template <>
+struct is_unsigned<unsigned int> : true_type {};
+
+template <>
+struct is_unsigned<unsigned long> : true_type {};
+
+#if ARDUINOJSON_USE_LONG_LONG
+template <>
+struct is_unsigned<unsigned long long> : true_type {};
+#endif
+#if ARDUINOJSON_USE_INT64
+template <>
+struct is_unsigned<unsigned __int64> : true_type {};
+#endif
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/RemoveConst.hpp b/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
similarity index 73%
rename from src/ArduinoJson/TypeTraits/RemoveConst.hpp
rename to src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
index 39d4cb5a..9cb7421b 100644
--- a/src/ArduinoJson/TypeTraits/RemoveConst.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/remove_const.hpp
@@ -9,12 +9,12 @@ namespace Internals {
 
 // A meta-function that return the type T without the const modifier
 template <typename T>
-struct RemoveConst {
+struct remove_const {
   typedef T type;
 };
 template <typename T>
-struct RemoveConst<const T> {
+struct remove_const<const T> {
   typedef T type;
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/TypeTraits/RemoveReference.hpp b/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
similarity index 73%
rename from src/ArduinoJson/TypeTraits/RemoveReference.hpp
rename to src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
index 395a1288..f0103dd2 100644
--- a/src/ArduinoJson/TypeTraits/RemoveReference.hpp
+++ b/src/ArduinoJson/Polyfills/type_traits/remove_reference.hpp
@@ -9,12 +9,12 @@ namespace Internals {
 
 // A meta-function that return the type T without the reference modifier.
 template <typename T>
-struct RemoveReference {
+struct remove_reference {
   typedef T type;
 };
 template <typename T>
-struct RemoveReference<T&> {
+struct remove_reference<T&> {
   typedef T type;
 };
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/StaticJsonDocument.hpp b/src/ArduinoJson/StaticJsonDocument.hpp
index b111485c..beab5ce4 100644
--- a/src/ArduinoJson/StaticJsonDocument.hpp
+++ b/src/ArduinoJson/StaticJsonDocument.hpp
@@ -35,8 +35,8 @@ class StaticJsonDocument {
 
   // JsonObject& to<JsonObject>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonObject>::value,
-                               JsonObject&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonObject>::value,
+                                JsonObject&>::type
   to() {
     clear();
     JsonObject* object = new (&_buffer) JsonObject(&_buffer);
@@ -47,8 +47,8 @@ class StaticJsonDocument {
 
   // JsonArray& to<JsonArray>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonArray>::value,
-                               JsonArray&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonArray>::value,
+                                JsonArray&>::type
   to() {
     clear();
     JsonArray* array = new (&_buffer) JsonArray(&_buffer);
@@ -59,8 +59,8 @@ class StaticJsonDocument {
 
   // JsonVariant to<JsonVariant>()
   template <typename T>
-  typename Internals::EnableIf<Internals::IsSame<T, JsonVariant>::value,
-                               T&>::type
+  typename Internals::enable_if<Internals::is_same<T, JsonVariant>::value,
+                                T&>::type
   to() {
     clear();
     return _root;
diff --git a/src/ArduinoJson/Strings/CharPointer.hpp b/src/ArduinoJson/Strings/CharPointer.hpp
index 2b804ab3..07a08284 100644
--- a/src/ArduinoJson/Strings/CharPointer.hpp
+++ b/src/ArduinoJson/Strings/CharPointer.hpp
@@ -30,13 +30,13 @@ struct CharPointerTraits {
 
   static const bool has_append = false;
   static const bool has_equals = true;
-  static const bool should_duplicate = !IsConst<TChar>::value;
+  static const bool should_duplicate = !is_const<TChar>::value;
 };
 
 // char*, unsigned char*, signed char*
 // const char*, const unsigned char*, const signed char*
 template <typename TChar>
-struct StringTraits<TChar*, typename EnableIf<IsChar<TChar>::value>::type>
+struct StringTraits<TChar*, typename enable_if<sizeof(TChar) == 1>::type>
     : CharPointerTraits<TChar> {};
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
diff --git a/src/ArduinoJson/Strings/StringTraits.hpp b/src/ArduinoJson/Strings/StringTraits.hpp
index 5201c172..8b62e978 100644
--- a/src/ArduinoJson/Strings/StringTraits.hpp
+++ b/src/ArduinoJson/Strings/StringTraits.hpp
@@ -6,11 +6,7 @@
 
 #include <string.h>
 #include "../Configuration.hpp"
-#include "../TypeTraits/EnableIf.hpp"
-#include "../TypeTraits/IsBaseOf.hpp"
-#include "../TypeTraits/IsChar.hpp"
-#include "../TypeTraits/IsConst.hpp"
-#include "../TypeTraits/RemoveReference.hpp"
+#include "../Polyfills/type_traits.hpp"
 
 namespace ArduinoJson {
 namespace Internals {
@@ -26,8 +22,8 @@ struct StringTraits<const TString, void> : StringTraits<TString> {};
 
 template <typename TString>
 struct StringTraits<TString&, void> : StringTraits<TString> {};
-}
-}
+}  // namespace Internals
+}  // namespace ArduinoJson
 
 #include "CharPointer.hpp"
 #include "FlashString.hpp"
diff --git a/src/ArduinoJson/TypeTraits/IsArray.hpp b/src/ArduinoJson/TypeTraits/IsArray.hpp
deleted file mode 100644
index 25992311..00000000
--- a/src/ArduinoJson/TypeTraits/IsArray.hpp
+++ /dev/null
@@ -1,24 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that return the type T without the const modifier
-template <typename T>
-struct IsArray {
-  static const bool value = false;
-};
-template <typename T>
-struct IsArray<T[]> {
-  static const bool value = true;
-};
-template <typename T, size_t N>
-struct IsArray<T[N]> {
-  static const bool value = true;
-};
-}
-}
diff --git a/src/ArduinoJson/TypeTraits/IsChar.hpp b/src/ArduinoJson/TypeTraits/IsChar.hpp
deleted file mode 100644
index d97cec21..00000000
--- a/src/ArduinoJson/TypeTraits/IsChar.hpp
+++ /dev/null
@@ -1,23 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-#include "IsSame.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that returns true if T is a charater
-template <typename T>
-struct IsChar {
-  static const bool value = IsSame<T, char>::value ||
-                            IsSame<T, signed char>::value ||
-                            IsSame<T, unsigned char>::value;
-};
-
-template <typename T>
-struct IsChar<const T> : IsChar<T> {};
-}
-}
diff --git a/src/ArduinoJson/TypeTraits/IsFloatingPoint.hpp b/src/ArduinoJson/TypeTraits/IsFloatingPoint.hpp
deleted file mode 100644
index e41a6824..00000000
--- a/src/ArduinoJson/TypeTraits/IsFloatingPoint.hpp
+++ /dev/null
@@ -1,18 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-#include "IsSame.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that returns true if T is a floating point type
-template <typename T>
-struct IsFloatingPoint {
-  static const bool value = IsSame<T, float>::value || IsSame<T, double>::value;
-};
-}
-}
diff --git a/src/ArduinoJson/TypeTraits/IsIntegral.hpp b/src/ArduinoJson/TypeTraits/IsIntegral.hpp
deleted file mode 100644
index 17ae5f28..00000000
--- a/src/ArduinoJson/TypeTraits/IsIntegral.hpp
+++ /dev/null
@@ -1,26 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-#include "IsSame.hpp"
-#include "IsSignedIntegral.hpp"
-#include "IsUnsignedIntegral.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that returns true if T is an integral type.
-template <typename T>
-struct IsIntegral {
-  static const bool value = IsSignedIntegral<T>::value ||
-                            IsUnsignedIntegral<T>::value ||
-                            IsSame<T, char>::value;
-  // CAUTION: differs from std::is_integral as it doesn't include bool
-};
-
-template <typename T>
-struct IsIntegral<const T> : IsIntegral<T> {};
-}
-}
diff --git a/src/ArduinoJson/TypeTraits/IsSignedIntegral.hpp b/src/ArduinoJson/TypeTraits/IsSignedIntegral.hpp
deleted file mode 100644
index 7334eb9c..00000000
--- a/src/ArduinoJson/TypeTraits/IsSignedIntegral.hpp
+++ /dev/null
@@ -1,28 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-#include "../Configuration.hpp"
-#include "IsSame.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that returns true if T is an integral type.
-template <typename T>
-struct IsSignedIntegral {
-  static const bool value =
-      IsSame<T, signed char>::value || IsSame<T, signed short>::value ||
-      IsSame<T, signed int>::value || IsSame<T, signed long>::value ||
-#if ARDUINOJSON_USE_LONG_LONG
-      IsSame<T, signed long long>::value ||
-#endif
-#if ARDUINOJSON_USE_INT64
-      IsSame<T, signed __int64>::value ||
-#endif
-      false;
-};
-}
-}
diff --git a/src/ArduinoJson/TypeTraits/IsUnsignedIntegral.hpp b/src/ArduinoJson/TypeTraits/IsUnsignedIntegral.hpp
deleted file mode 100644
index 938423f5..00000000
--- a/src/ArduinoJson/TypeTraits/IsUnsignedIntegral.hpp
+++ /dev/null
@@ -1,28 +0,0 @@
-// ArduinoJson - arduinojson.org
-// Copyright Benoit Blanchon 2014-2018
-// MIT License
-
-#pragma once
-
-#include "../Configuration.hpp"
-#include "IsSame.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-
-// A meta-function that returns true if T is an integral type.
-template <typename T>
-struct IsUnsignedIntegral {
-  static const bool value =
-      IsSame<T, unsigned char>::value || IsSame<T, unsigned short>::value ||
-      IsSame<T, unsigned int>::value || IsSame<T, unsigned long>::value ||
-#if ARDUINOJSON_USE_LONG_LONG
-      IsSame<T, unsigned long long>::value ||
-#endif
-#if ARDUINOJSON_USE_INT64
-      IsSame<T, unsigned __int64>::value ||
-#endif
-      false;
-};
-}
-}
diff --git a/src/ArduinoJson/Writing/Writer.hpp b/src/ArduinoJson/Writing/Writer.hpp
index 7a529279..66c57a53 100644
--- a/src/ArduinoJson/Writing/Writer.hpp
+++ b/src/ArduinoJson/Writing/Writer.hpp
@@ -21,7 +21,7 @@ struct Writer {
 
 template <typename TJsonBuffer, typename TChar>
 struct Writer<TJsonBuffer, TChar*,
-              typename EnableIf<!IsConst<TChar>::value>::type> {
+              typename enable_if<!is_const<TChar>::value>::type> {
   typedef StringWriter<TChar> type;
 
   static type create(TJsonBuffer&, TChar* input) {
diff --git a/src/ArduinoJson/deserializeJson.hpp b/src/ArduinoJson/deserializeJson.hpp
index b0eafc8b..d4e11834 100644
--- a/src/ArduinoJson/deserializeJson.hpp
+++ b/src/ArduinoJson/deserializeJson.hpp
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include "Json/Deserialization/JsonDeserializer.hpp"
+#include "Json/JsonDeserializer.hpp"
 #include "Reading/Reader.hpp"
 #include "Writing/Writer.hpp"
 
@@ -13,8 +13,8 @@ namespace ArduinoJson {
 // TDocument = DynamicJsonDocument, StaticJsonDocument
 // TString = const std::string&, const String&
 template <typename TDocument, typename TString>
-typename Internals::EnableIf<!Internals::IsArray<TString>::value,
-                             DeserializationError>::type
+typename Internals::enable_if<!Internals::is_array<TString>::value,
+                              DeserializationError>::type
 deserializeJson(TDocument &doc, const TString &input) {
   using namespace Internals;
   return makeJsonDeserializer(&doc.buffer(), makeReader(input),
diff --git a/src/ArduinoJson/deserializeMsgPack.hpp b/src/ArduinoJson/deserializeMsgPack.hpp
index 9256a411..7c38cdc5 100644
--- a/src/ArduinoJson/deserializeMsgPack.hpp
+++ b/src/ArduinoJson/deserializeMsgPack.hpp
@@ -13,8 +13,8 @@ namespace ArduinoJson {
 // TDocument = DynamicJsonDocument, StaticJsonDocument
 // TString = const std::string&, const String&
 template <typename TDocument, typename TString>
-typename Internals::EnableIf<!Internals::IsArray<TString>::value,
-                             DeserializationError>::type
+typename Internals::enable_if<!Internals::is_array<TString>::value,
+                              DeserializationError>::type
 deserializeMsgPack(TDocument &doc, const TString &input) {
   using namespace Internals;
   return makeMsgPackDeserializer(&doc.buffer(), makeReader(input),
diff --git a/test/JsonWriter/writeFloat.cpp b/test/JsonWriter/writeFloat.cpp
index aa06552b..73bc1912 100644
--- a/test/JsonWriter/writeFloat.cpp
+++ b/test/JsonWriter/writeFloat.cpp
@@ -6,7 +6,7 @@
 #include <limits>
 #include <string>
 
-#include <ArduinoJson/Json/Serialization/JsonWriter.hpp>
+#include <ArduinoJson/Json/JsonWriter.hpp>
 #include <ArduinoJson/Print/DynamicStringBuilder.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/JsonWriter/writeString.cpp b/test/JsonWriter/writeString.cpp
index eded06e3..104bc104 100644
--- a/test/JsonWriter/writeString.cpp
+++ b/test/JsonWriter/writeString.cpp
@@ -4,7 +4,7 @@
 
 #include <catch.hpp>
 
-#include <ArduinoJson/Json/Serialization/JsonWriter.hpp>
+#include <ArduinoJson/Json/JsonWriter.hpp>
 #include <ArduinoJson/Print/StaticStringBuilder.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/Misc/FloatParts.cpp b/test/Misc/FloatParts.cpp
index d9cf18a1..f3e10a74 100644
--- a/test/Misc/FloatParts.cpp
+++ b/test/Misc/FloatParts.cpp
@@ -2,7 +2,7 @@
 // Copyright Benoit Blanchon 2014-2018
 // MIT License
 
-#include <ArduinoJson/Json/Serialization/FloatParts.hpp>
+#include <ArduinoJson/Numbers/FloatParts.hpp>
 #include <catch.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/Misc/TypeTraits.cpp b/test/Misc/TypeTraits.cpp
index 8d730b21..41cdebbc 100644
--- a/test/Misc/TypeTraits.cpp
+++ b/test/Misc/TypeTraits.cpp
@@ -7,21 +7,21 @@
 
 using namespace ArduinoJson::Internals;
 
-TEST_CASE("TypeTraits") {
-  SECTION("IsBaseOf") {
+TEST_CASE("Polyfills/type_traits") {
+  SECTION("is_base_of") {
     REQUIRE_FALSE(
-        static_cast<bool>(IsBaseOf<std::istream, std::ostringstream>::value));
+        static_cast<bool>(is_base_of<std::istream, std::ostringstream>::value));
     REQUIRE(
-        static_cast<bool>(IsBaseOf<std::istream, std::istringstream>::value));
+        static_cast<bool>(is_base_of<std::istream, std::istringstream>::value));
     REQUIRE(static_cast<bool>(
-        IsBaseOf<JsonVariantBase<JsonObjectSubscript<const char*> >,
-                 JsonObjectSubscript<const char*> >::value));
+        is_base_of<JsonVariantBase<JsonObjectSubscript<const char*> >,
+                   JsonObjectSubscript<const char*> >::value));
   }
 
-  SECTION("IsArray") {
-    REQUIRE_FALSE((IsArray<const char*>::value));
-    REQUIRE((IsArray<const char[]>::value));
-    REQUIRE((IsArray<const char[10]>::value));
+  SECTION("is_array") {
+    REQUIRE_FALSE((is_array<const char*>::value));
+    REQUIRE((is_array<const char[]>::value));
+    REQUIRE((is_array<const char[10]>::value));
   }
 
   SECTION("IsVariant") {
@@ -30,8 +30,30 @@ TEST_CASE("TypeTraits") {
     REQUIRE(static_cast<bool>(IsVariant<JsonVariant>::value));
   }
 
-  SECTION("IsConst") {
-    REQUIRE_FALSE((IsConst<char>::value));
-    REQUIRE((IsConst<const char>::value));
+  SECTION("is_const") {
+    CHECK(is_const<char>::value == false);
+    CHECK(is_const<const char>::value == true);
+  }
+
+  SECTION("is_signed") {
+    CHECK(is_signed<char>::value == true);
+    CHECK(is_signed<signed char>::value == true);
+    CHECK(is_signed<signed int>::value == true);
+    CHECK(is_signed<signed short>::value == true);
+    CHECK(is_signed<signed long>::value == true);
+    CHECK(is_signed<float>::value == true);
+    CHECK(is_signed<double>::value == true);
+    CHECK(is_signed<bool>::value == false);
+  }
+
+  SECTION("is_unsigned") {
+    CHECK(is_unsigned<unsigned char>::value == true);
+    CHECK(is_unsigned<unsigned int>::value == true);
+    CHECK(is_unsigned<unsigned short>::value == true);
+    CHECK(is_unsigned<unsigned long>::value == true);
+    CHECK(is_unsigned<bool>::value == true);
+    CHECK(is_unsigned<char>::value == false);
+    CHECK(is_unsigned<float>::value == false);
+    CHECK(is_unsigned<double>::value == false);
   }
 }
diff --git a/test/Polyfills/isFloat.cpp b/test/Polyfills/isFloat.cpp
index f4fbe16b..3d77ac49 100644
--- a/test/Polyfills/isFloat.cpp
+++ b/test/Polyfills/isFloat.cpp
@@ -2,7 +2,7 @@
 // Copyright Benoit Blanchon 2014-2018
 // MIT License
 
-#include <ArduinoJson/Text/isFloat.hpp>
+#include <ArduinoJson/Numbers/isFloat.hpp>
 #include <catch.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/Polyfills/isInteger.cpp b/test/Polyfills/isInteger.cpp
index 8cc74dd1..a2f11fc9 100644
--- a/test/Polyfills/isInteger.cpp
+++ b/test/Polyfills/isInteger.cpp
@@ -2,7 +2,7 @@
 // Copyright Benoit Blanchon 2014-2018
 // MIT License
 
-#include <ArduinoJson/Text/isInteger.hpp>
+#include <ArduinoJson/Numbers/isInteger.hpp>
 #include <catch.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/Polyfills/parseFloat.cpp b/test/Polyfills/parseFloat.cpp
index bd481ea2..18cb0cfb 100644
--- a/test/Polyfills/parseFloat.cpp
+++ b/test/Polyfills/parseFloat.cpp
@@ -2,7 +2,7 @@
 // Copyright Benoit Blanchon 2014-2018
 // MIT License
 
-#include <ArduinoJson/Text/parseFloat.hpp>
+#include <ArduinoJson/Numbers/parseFloat.hpp>
 #include <catch.hpp>
 
 using namespace ArduinoJson::Internals;
diff --git a/test/Polyfills/parseInteger.cpp b/test/Polyfills/parseInteger.cpp
index afac3bf5..786834b1 100644
--- a/test/Polyfills/parseInteger.cpp
+++ b/test/Polyfills/parseInteger.cpp
@@ -3,7 +3,7 @@
 // MIT License
 
 #include <stdint.h>
-#include <ArduinoJson/Text/parseInteger.hpp>
+#include <ArduinoJson/Numbers/parseInteger.hpp>
 #include <catch.hpp>
 
 using namespace ArduinoJson::Internals;