Reorganized writer classes

src/ArduinoJson/Strings/IsWriteableString.hpp

@@ -0,0 +1,37 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#pragma once
+
+#include <ArduinoJson/Configuration.hpp>
+#include <ArduinoJson/Polyfills/type_traits.hpp>
+
+#if ARDUINOJSON_ENABLE_ARDUINO_STRING
+#include <WString.h>
+#endif
+
+#if ARDUINOJSON_ENABLE_STD_STRING
+#include <string>
+#endif
+
+namespace ARDUINOJSON_NAMESPACE {
+
+template <typename>
+struct IsWriteableString : false_type {};
+
+#if ARDUINOJSON_ENABLE_ARDUINO_STRING
+
+template <>
+struct IsWriteableString< ::String> : true_type {};
+
+#endif
+
+#if ARDUINOJSON_ENABLE_STD_STRING
+
+template <typename TCharTraits, typename TAllocator>
+struct IsWriteableString<std::basic_string<char, TCharTraits, TAllocator> >
+    : true_type {};
+
+#endif
+}  // namespace ARDUINOJSON_NAMESPACE