c++split函数

#include <iostream>
#include <string>
#include <vector>

using namespace std;

vector<string> split(const string& src, string delimit, string null_subst = "")
{
    typedef basic_string<char>::size_type s_t;
    static const s_t npos = -1;

    if (src.empty() || delimit.empty())
    {
        throw "split:empty string\0";
    }
    vector<string> v;
    s_t deli_len = delimit.size();
    s_t index = npos, last_search_position = 0;
    while ((index = src.find(delimit, last_search_position)) != npos)
    {
        if (index == last_search_position)
        {
            v.push_back(null_subst);
        }
        else
        {
            v.push_back(src.substr(last_search_position, index
                    - last_search_position));
        }
        last_search_position = index + deli_len;