If you are using Cocos2d-x to write your app in C++, you must first implement all the steps for Tapjoy iOS integration for your Xcode project then use the TapjoyCpp.h header file.
#include "Tapjoy/TapjoyCpp.h" // Tapjoy C++ API
using namespace tapjoy;
Tapjoy::trackEvent("some event");
Full details here.
TJPrivacyPolicyHandle policyHandle;
policyHandle = TJPrivacyPolicy::getPrivacyPolicy();
TJPrivacyPolicy::subjectToGDPR(policyHandle,true);
TJPrivacyPolicy::setUserConsent(policyHandle, "1″);
TJPrivacyPolicy::setUSPrivacy(policyHandle, "1YNY");
TJPrivacyPolicy::belowConsentAge(policyHandle, true);