bool_args.cpp

/*

Example output:

proc:
  Got opt1
proc:
  Got opt1
  Got opt3
proc:
  Got opt1
  Got opt2
  Got opt4
proc:
  Got opt1
  Got opt4
proc:
  Got opt1
  Got opt3
  Got opt4

I think this requires c++11

To help know the meaning of true vs false, use the option name for that.
like .overwrite=1 means that we overwrite or .overwrite=0 means that we don't

If you want the meaning of true or false to be the opposite then you 
would do .no_overwrite=0 for yes we want to overwrite



*/


#include <stdio.h>

struct proc_flags_t {  // this is a bit field construct sizeof(proc_flags_t) == sizeof(unsigned char)
    unsigned char opt1:1,opt2:1,opt3:1,opt4:1;
};

// use proc_flags_t&&flags if you want to pass a pointer  (actually a reference, but same thing)
void proc(proc_flags_t flags) {
    printf("proc:\n");
    if (flags.opt1) printf("  Got opt1\n");
    if (flags.opt2) printf("  Got opt2\n");
    if (flags.opt3) printf("  Got opt3\n");
    if (flags.opt4) printf("  Got opt4\n");
}

int main() {
    proc({ .opt1=1 });
    proc({ .opt1=1, .opt3=1 });
    proc({ .opt1=1, .opt2=1, .opt4=1 });
    proc({ .opt1=1, .opt2=0, .opt4=1 });
    proc({ 1, 0, 1, 1 });
}