#include<iostream>
#include<string>
using namespace std;

int main(){
string a="123";
char *temp=new char[];
temp=dynamic_cast<char*>(&a);
cout<<temp<<endl;
cout<<a<<endl;
return 0;
}

#include <iostream>
using namespace std;
int main()
{
string a="123";
const char* temp=a.data();
cout<<temp<<endl;
cout<<a.data()<<endl;
system("pause");
return 0;
}

#include<iostream>
#include<string>
using namespace std;

int main(int argc, char* argv[])
{
string a="123";
char *temp=new char[100];
strcpy(temp, a.c_str());

cout<<temp<<endl;
cout<<a<<endl;
return 0;
return 0;
}

谢谢大家的回答，我也感觉到受教了！