Call back function, error: typedef 'cb' is initialized (use __typeof__ instead)

Projects Programming
1

Hi,

i want to write a library with a call back function. This is what i have (just whats important).
RemotePedal.h:

#ifndef RemotePedal_h
#define RemotePedal_h

#include "Arduino.h"

extern "C" {
// callback function
    typedef void (*FunctionChangedCallback)(Function *func); // line 24
}

struct Function {
  int functionID;
  String name;
  byte value;
};

class RemotePedal
{
public:
    RemotePedal();
    void attachCB_FunctionChanged(FunctionChangedCallback newFunction); // line 46
private:
    FunctionChangedCallback cbFunction; // line 60
};

#endif

The errors i get:

C:\Program Files\arduino\libraries\RemotePedal/RemotePedal.h:24: error: typedef 'FunctionChangedCallback' is initialized (use typeof instead)
C:\Program Files\arduino\libraries\RemotePedal/RemotePedal.h:24: error: 'Function' was not declared in this scope
C:\Program Files\arduino\libraries\RemotePedal/RemotePedal.h:24: error: 'func' was not declared in this scope
C:\Program Files\arduino\libraries\RemotePedal/RemotePedal.h:46: error: 'FunctionChangedCallback' has not been declared
C:\Program Files\arduino\libraries\RemotePedal/RemotePedal.h:60: error: 'FunctionChangedCallback' does not name a type

I want a call back function which takes a pointer to a "Function" struct as an argument.
I have absolutely no idea what's wrong or how to correct it. Can someone help me?

Thanks in advance, dusti

2
  1. The struct definition should be inside the "C"
  2. The struct definition must be before the function typedef
  3. The function typedef is incomplete: the keyword "struct" is missing before "Function"

Oliver

3

Thank you, you solved my problems :slight_smile: