C++: No Known Conversion from 'FILE *()' to 'FILE *'

I've been trying to remove characters for the middle of a file using a temporary file. However, when I call

    fputc(c, tmpfile);

where c is a char and tmpfile is a FILE*, I get the following when compiling:

dnhobf_fxn.cc:36:7: error: no matching function for call to 'fputc'
      fputc(c, tmpfile);
      ^~~~~
/usr/include/stdio.h:243:6: note: candidate function not viable: no known
      conversion from 'FILE *()' to 'FILE *' (aka '__sFILE *') for 2nd argument
int      fputc(int, FILE *);
         ^

What exactly is the issue here, and how can I rectify it? I am unfamiliar with the difference between a FILE *() and a FILE *.