simple test of JSON decoding in ObjC

test_json.m

#import <Foundation/Foundation.h>
#include <string.h>

int main(int argc, char *argv[])
{
    if (argc != 2)
    {
        printf("pass JSON in a single argument\n");
        return 1;
    }

    __auto_type json = argv[1];
    __auto_type data = [NSData dataWithBytesNoCopy:json length:strlen(json)];
    NSError *err = nil;
    id obj = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&err];
    NSLog(@"%@", obj ?: err);
    return 0;
}