request for member 'write' in ..., which is of non-class type 'char*'
Applies to ArduinoJson 6.13 and above
request for member 'write' in '...::Writer<char*, void>::_dest', which is of non-class type 'char*'
The compiler looked for a member function called
write() in the type
char*, meaning it confused a
char pointer for a custom writer class.
When does it occur?
This error occurs when you pass a
serializeJson() but forget to pass the third argument.
serializeJson(doc, ptr); // request for member 'write' in ..., which is of non-class type 'char*'
How to fix it?
To fix this error, you must pass the size of the destination buffer as the third argument, like so:
serializeJson(doc, ptr, size); // OK
When can I omit the third argument?
In the examples, you may have seen that I didn’t use the size argument; that’s because the second argument was not a
char* but a
serializeJson() was able to infer the value of
N from the type.