ARDUINOJSON_ENABLE_STD_STRING
The macro ARDUINOJSON_ENABLE_STD_STRING enables the support of the type std::string in the library.
If ARDUINOJSON_ENABLE_STD_STRING is defined 1, then std::string is supported.
Default value
ArduinoJson tries to guess whether std::string is available or not, based on the presence of the ARDUINO macro.
The default value of ARDUINOJSON_ENABLE_STD_STRING is:
0ifARDUINOis defined,1otherwise.
In other words, std::string is supported as soon as you work outside of Arduino.
How to force support for std::string?
If you need to force the support of std::string, add the following line at the top of your program:
#define ARDUINOJSON_ENABLE_STD_STRING 1
#include <ArduinoJson.h>
How to disable support for std::string
If for some reason, you need to disable the support for std::string, add the following line at the top of your program:
#define ARDUINOJSON_ENABLE_STD_STRING 0
#include <ArduinoJson.h>