c++ 多态练习，我这样写有内存泄漏吗

循环执行读取配置，我用 _CrtDumpMemoryLeaks();
老说我有内存泄漏

#include <iostream>
#include <vector>

using namespace std;

class configBase
{
public:
    virtual void loadData()=0;
    virtual ~configBase(){}
};

class ConfigA:public configBase
{
public:
    virtual void loadData()
    {
        cout << "this configA" << endl;
    }
    ~ConfigA()
    {
        cout << "~A "<< endl;
    }
};

class ConfigB :public configBase
{
public:
    virtual void loadData()
    {
        cout << "this configB" << endl;
    }
    ~ConfigB()
    {
        cout << "~B" << endl;
    }
};

class ConfigC :public configBase
{
public:
    virtual void loadData()
    {
        cout << "this configC" << endl;
    }
    ~ConfigC()
    {
        cout << "~C" << endl;
    }
};

class ConfigManager
{
public:
    ConfigManager()
    {
        ConfigA* a=new ConfigA();
        ConfigB* b=new ConfigB();
        ConfigC* c=new ConfigC();
        configVec.push_back(a);
        configVec.push_back(b);
        configVec.push_back(c);
    }

    void showConfig()
    {
        for (auto con:configVec)
        {
            con->loadData();
        }
    }
    ~ConfigManager()
    {
        for (auto con : configVec)
        {
            delete con;
        }
    }
private:
    vector<configBase*> configVec;
};
int main()
{
    ConfigManager con;
    con.showConfig();
}

https://bbs.csdn.net/topics/370070232