通过 Box2d 中的 NSNotificationCenter 发送类对象C++。错误：没有从 'MyContact' 到 'id' 的可行转换

我尝试在box2d *cocos2d*中实现联系人侦听器。我想在PostSolve函数中集成NSNotificationCenter，但是当我尝试指向对象：参数时，我遇到了错误：

No viable conversion from 'MyContact' to 'id'

如何通过 NSNotificationCenter 发送 MyContact 对象？

MyContactListener 类

 //
    //  MyContactListener.m
    //  Box2DPong
    //
    //  Created by Ray Wenderlich on 2/18/10.
    //  Copyright 2010 Ray Wenderlich. All rights reserved.
    //
    #import "MyContactListener.h"
    #import "ConfigMacro.h"
    MyContactListener::MyContactListener() : _contacts(),_contactsObjects(){}
    MyContactListener::~MyContactListener() {}
    void MyContactListener::BeginContact(b2Contact* contact) {
        b2Body *bodyA = contact->GetFixtureA()->GetBody();
        b2Body *bodyB = contact->GetFixtureB()->GetBody();
        if(bodyA->GetUserData() != NULL && bodyB->GetUserData() != NULL)
        {
            MyContact myContact = { contact->GetFixtureA(), contact->GetFixtureB() };
            _contacts.push_back(myContact);
        }
    }
    void MyContactListener::EndContact(b2Contact* contact) {
        MyContact myContact = { contact->GetFixtureA(), contact->GetFixtureB() };
        std::vector<MyContact>::iterator pos;
        pos = std::find(_contacts.begin(), _contacts.end(), myContact);
        if (pos != _contacts.end()) {
            _contacts.erase(pos);
        }
    }
   void MyContactListener::PreSolve(b2Contact* contact, const b2Manifold* oldManifold) {}
    void MyContactListener::PostSolve(b2Contact* contact, const b2ContactImpulse* impulse) {
        b2Body *bodyA = contact->GetFixtureA()->GetBody();
        b2Body *bodyB = contact->GetFixtureB()->GetBody();
        if(bodyA->GetUserData() != NULL && bodyB->GetUserData() != NULL)
        {
        int32 count = contact->GetManifold()->pointCount;
        float32 maxImpulse = 0.0f;
        b2Vec2 collision;
        for (int32 i = 0; i < count; ++i) {
            maxImpulse = b2Max(maxImpulse, impulse->normalImpulses[i]);
            if (i == 0) {
                b2WorldManifold worldManifold;
                contact->GetWorldManifold(&worldManifold);
                collision = worldManifold.points[0];
            }
        }
        MyContact myContact = { contact->GetFixtureA(), contact->GetFixtureB(), maxImpulse, collision };
        [[NSNotificationCenter defaultCenter] postNotificationName:kReceivedImpulse object:myContact userInfo:nil];
        }    
    }