std::string 字符串切割

在很多字符串类库里都实现了split函数。不过在std里没有实现。在这里拿出几个：

1. 用单字符作为分隔

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

 vector<string> split(string strtem,char a)
 {
         vector<string> strvec;

         string::size_type pos1, pos2;
         pos2 = strtem.find(a);
         pos1 = ;
         while (string::npos != pos2)
         {
                 strvec.push_back(strtem.substr(pos1, pos2 - pos1));

                 pos1 = pos2 + ;
                 pos2 = strtem.find(a, pos1);
         }
         strvec.push_back(strtem.substr(pos1));
         return strvec;
 }

2. 由多个分隔符来分隔：

 std::vector<std::string> splitString(std::string srcStr, std::string delimStr, bool repeatedCharIgnored)
 {
     std::vector<std::string> resultStringVector;
     std::replace_if(srcStr.begin(), srcStr.end(),
         [&](const char& c){if (delimStr.find(c) != std::string::npos){ return true; } else{ return false; }}/*pred*/, delimStr.at());
     //将出现的所有分隔符都替换成为一个相同的字符（分隔符字符串的第一个）
     size_t pos = srcStr.find(delimStr.at());
     std::string addedString = "";
     while (pos != std::string::npos) {
         addedString = srcStr.substr(, pos);
         if (!addedString.empty() || !repeatedCharIgnored) {
             resultStringVector.push_back(addedString);
         }
         srcStr.erase(srcStr.begin(), srcStr.begin() + pos + );
         pos = srcStr.find(delimStr.at());
     }
     addedString = srcStr;
     if (!addedString.empty() || !repeatedCharIgnored) {
         resultStringVector.push_back(addedString);
     }
     return resultStringVector;
 }