Added support for Stream (issue #300)

include/ArduinoJson/StringTraits/FlashString.hpp

@@ -0,0 +1,44 @@
+// Copyright Benoit Blanchon 2014-2016
+// MIT License
+//
+// Arduino JSON library
+// https://github.com/bblanchon/ArduinoJson
+// If you like this project, please add a star!
+
+#pragma once
+
+namespace ArduinoJson {
+namespace Internals {
+template <>
+struct StringFuncs<const __FlashStringHelper*, void> {
+  class Iterator {
+    const char* _ptr;
+
+   public:
+    Iterator(const __FlashStringHelper* ptr)
+        : _ptr(reinterpret_cast<const char*>(ptr)) {}
+
+    char next() {
+      return pgm_read_byte_near(_ptr++);
+    }
+  };
+
+  static bool equals(const __FlashStringHelper* str, const char* expected) {
+    return strcmp_P(expected, (PGM_P)str) == 0;
+  }
+
+  template <typename Buffer>
+  static char* duplicate(const __FlashStringHelper* str, Buffer* buffer) {
+    if (!str) return NULL;
+    size_t size = strlen_P((PGM_P)str) + 1;
+    void* dup = buffer->alloc(size);
+    if (dup != NULL) memcpy_P(dup, (PGM_P)str, size);
+    return static_cast<char*>(dup);
+  }
+
+  static const bool has_append = false;
+  static const bool has_equals = true;
+  static const bool should_duplicate = true;
+};
+}
+}