Read userdefaults with c++ on Mac

userdefaults.cpp

#include <CoreFoundation/CoreFoundation.h>

std::string CIdHelper::getCId(int env) {
  CFStringRef bundle_id = CFSTR("bundle_id");
  CFStringRef key = CFSTR("key");
  CFPropertyListRef cid = CFPreferencesCopyAppValue(key, bundle_id);
  if (!cid) {
    return {};
  }
  char buffer[1024];
  if (!CFStringGetCString((CFStringRef)cid, buffer, sizeof(buffer), kCFStringEncodingUTF8)) {
    CFRelease(cid);
    return {};
  }
  CFRelease(cid);
  return std::string(buffer);