User can now use a JsonString as a key or a value

src/ArduinoJson/Strings/SizedRamStringAdapter.hpp

@@ -0,0 +1,50 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include <string.h>  // strcmp
+
+namespace ARDUINOJSON_NAMESPACE {
+
+class SizedRamStringAdapter {
+ public:
+  SizedRamStringAdapter(const char* str, size_t n) : _str(str), _size(n) {}
+
+  bool equals(const char* expected) const {
+    const char* actual = reinterpret_cast<const char*>(_str);
+    if (!actual || !expected) return actual == expected;
+    return strcmp(actual, expected) == 0;
+  }
+
+  bool isNull() const {
+    return !_str;
+  }
+
+  char* save(MemoryPool* pool) const {
+    if (!_str) return NULL;
+    char* dup = pool->allocFrozenString(_size);
+    if (dup) memcpy(dup, _str, _size);
+    return dup;
+  }
+
+  size_t size() const {
+    return strlen(reinterpret_cast<const char*>(_str));
+  }
+
+  bool isStatic() const {
+    return false;
+  }
+
+ private:
+  const char* _str;
+  size_t _size;
+};
+
+template <typename TChar>
+inline SizedRamStringAdapter adaptString(const TChar* str, size_t size) {
+  return SizedRamStringAdapter(reinterpret_cast<const char*>(str), size);
+}
+
+}  // namespace ARDUINOJSON_NAMESPACE