fmt_plusminus - write '+' or '-'

       fmt_plusminus writes '-' to dest if source is negative, '+' if source is positive, nothing otherwise.  It
       returns the number of bytes written.

       fmt_plusminus does not append \0.

       If dest equals FMT_LEN (i.e. is zero), fmt_plusminus returns the number of bytes it would have written.

       fmt_plusminus - write '+' or '-'

fmt_minus(3), scan_plusminus(3)

                                                                                                fmt_plusminus(3)

#include<libowfat/fmt.h>

       size_t fmt_plusminus(char *dest,signed int source);