string::replace

 

#include <string>
#include <cctype>
#include <algorithm>
#include <iostream>
#include <list>
using namespace std;
class Base{
public:
        int data;
        Base(int y):data(y){}
};
Base *pt(int x){
        Base *tmp = new Base(x);
        return tmp;
}
int main()
{
        string str("this is a test");
        char rpV = '^';
        string::size_type pos = 0;
        while((pos = str.find(" ")) != string::npos){
                //replace(pos, nct1, nct2, ch); 用重复n次的c字符替换从指定位置pos长度为len的内容
                str.replace(pos,1,2, rpV);
                cout << str << endl;
        }
}