支持泛型vector的stringhelper

 

// string_helper.h
#pragma once
#include <string>
#include <sstream>
#include <vector>

template<typename T> T from_string(const std::string& s)
{
    std::istringstream is(s);
    T t;
    is >> t;
    return t;
}

template<typename T> void from_string(std::string& s, std::vector<T>& vec)
{
    size_t pos = 0;
    while( s.length() > 0 )
    {
        pos = s.find(',');
        if (pos != string::npos)
        {
            string ssub = s.substr(0, pos);
            vec.push_back(from_string<T>(sub));
            ss = s.substr(pos + 1, s.length());
        }
        else
        {
            vec.push_back(from_string<T>(s));
            s.clear();
        }
    }
}

template<typename T> std::string to_string(const T& t)
{
  std::ostringstream os;
  os << t;
  return os.str();
}

template<typename T> std::string to_string(std::vector<T>& vec)
{
    std::ostringstream os;
    std::vector<T>::iterator iter = vec.begin();
    while( iter != vec.end())
    {
        os << (*iter) << ',';
        iter++;
    }
    return os.str().substr(0, os.str().find_last_of(','));
}