Fix 'std::string' has not been declared (issue bblanchon#1967)

bblanchon · bblanchon · commit 259855a87b17 · 2023-09-13T18:13:18.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,11 @@
 ArduinoJson: change log
 =======================
 
+HEAD
+----
+
+* Fix error `'std::string' has not been declared` (issue #1967)
+
 v6.21.3 (2023-07-23)
 -------
 
diff --git a/extras/tests/Misc/CMakeLists.txt b/extras/tests/Misc/CMakeLists.txt
@@ -6,6 +6,7 @@ add_executable(MiscTests
 	arithmeticCompare.cpp
 	conflicts.cpp
 	FloatParts.cpp
+	issue1967.cpp
 	JsonString.cpp
 	NoArduinoHeader.cpp
 	printable.cpp
diff --git a/extras/tests/Misc/issue1967.cpp b/extras/tests/Misc/issue1967.cpp
@@ -0,0 +1,13 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2023, Benoit BLANCHON
+// MIT License
+
+// we expect ArduinoJson.h to include <string>
+#define ARDUINOJSON_ENABLE_STD_STRING 1
+
+// but we don't want it to included accidentally
+#undef ARDUINO
+#define ARDUINOJSON_ENABLE_STD_STREAM 0
+#define ARDUINOJSON_ENABLE_STRING_VIEW 0
+
+#include <ArduinoJson.h>
diff --git a/src/ArduinoJson/Variant/ConverterImpl.hpp b/src/ArduinoJson/Variant/ConverterImpl.hpp
@@ -8,6 +8,10 @@
 #include <ArduinoJson/Variant/JsonVariantConst.hpp>
 #include <ArduinoJson/Variant/VariantFunctions.hpp>
 
+#if ARDUINOJSON_ENABLE_STD_STRING
+#  include <string>
+#endif
+
 ARDUINOJSON_BEGIN_PUBLIC_NAMESPACE
 
 template <typename T, typename Enable>
