invalid use of void expression when passing a function as parameter

Question

I have a function called

GLOBAL char* GET_Enum(REC_NO  recNo )
{
  .....
}

also I have a function which take this function as an input like this

static void Dropdowns( char* param , 
                       char* title, 
                       char* (*enumFunction)(REC_NO),
                       int maxRecNo)
{
 .....
}

Then I call that function like this

Dropdowns("test", "Location", GET_Enum, 3);

But it doesn't compile and gives me the error below:

 error: invalid use of void expression

I have looked at this issues Link1 and Link2 which are relevant but I still can't see what I am doing wrong? any idea? Thanks

@JacekCz it is a framework that I am using so it doesn't make much sense if I give the full code. but I update it a bit to make more sense. — Zardaloop, Nov 05 '16 at 07:48
at first: what is GLOBAL, REC_NO. Sample cannot be compiled without — Jacek Cz, Nov 05 '16 at 07:50
thanks @JacekCz just change the Global to static, REC_NO is char[14] — Zardaloop, Nov 05 '16 at 08:00
The code you posted is fine. The error about the void expression is coming from something else, that you haven't showed us. — Steve Summit, Nov 05 '16 at 08:27

score 2 · Accepted Answer · answered Nov 05 '16 at 08:14

Seems You have error in other place, or give us wrong additional information.

Code (with explanation) compile very well, MSVC 2015

#include "stdafx.h"

static char* GET_Enum(char  recNo[14] )
{
    return NULL;
}

static void Dropdowns(char* param,
    char* title,
    char* (*enumFunction)(char[14]),
    int maxRecNo)
{
}
int main()
{
    Dropdowns("test", "Location", GET_Enum, 3);
    return 0;
}

========== Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========

invalid use of void expression when passing a function as parameter

1 Answers1