implement split with c++

#include <iostream>
#include <string>
#include <vector>
using namespace std;
using std::string;
using std::vector;
int split(vector<string>& list,const string& src)
{
    const char *p=src.c_str();
    char *p1,*p2;
    p1 = p2 = const_cast<char *>(p);

    while((*p2)!='\0')
    {
        if((*p2)==',')
        {
            list.push_back(string(p1,p2));
            p1=p2+1;
        }
        ++p2;
    }
    if (list.size()>0)
    {
        list.push_back(string(p1,p2));
    }
    return list.size();
}
int main(void)
{
    string a("ab");
    vector<string> list;
    split(list,a);
    cout<<list.size()<<endl;
        for (std::vector<string>::iterator iter = list.begin(); iter != list.end(); ++iter)
                {
                            std::cout << *iter << std::endl;
                                }
   
    return 0;
}