c++ - 将一串数据标记为结构 vector ？

Question

所以我有以下数据字符串，它是通过 TCP winsock 连接接收的，并且想进行高级标记化，将其转换为结构 vector ，其中每个结构代表一个记录。

std::string buf = "44:william:adama:commander:stuff\n33:luara:roslin:president:data\n"

struct table_t
{
    std::string key;
    std::string first;
    std::string last;
    std::string rank;
    std::additional;
};

字符串中的每条记录都由回车符分隔。我尝试拆分记录，但尚未拆分字段:

    void tokenize(std::string& str, std::vector< string >records)
{
    // Skip delimiters at beginning.
    std::string::size_type lastPos = str.find_first_not_of("\n", 0);
    // Find first "non-delimiter".
    std::string::size_type pos     = str.find_first_of("\n", lastPos);
    while (std::string::npos != pos || std::string::npos != lastPos)
    {
        // Found a token, add it to the vector.
        records.push_back(str.substr(lastPos, pos - lastPos));
        // Skip delimiters.  Note the "not_of"
        lastPos = str.find_first_not_of("\n", pos);
        // Find next "non-delimiter"
        pos = str.find_first_of("\n", lastPos);
    }
}

似乎完全没有必要再次重复所有代码以通过冒号(内部字段分隔符)将每条记录进一步标记到结构中并将每个结构插入 vector 中。我确信有更好的方法可以做到这一点，或者设计本身可能是错误的。

感谢您的帮助。

Answer 1

我的解决方案:

struct colon_separated_only: std::ctype<char> 
{
    colon_separated_only(): std::ctype<char>(get_table()) {}

    static std::ctype_base::mask const* get_table()
    {
        typedef std::ctype<char> cctype;
        static const cctype::mask *const_rc= cctype::classic_table();

        static cctype::mask rc[cctype::table_size];
        std::memcpy(rc, const_rc, cctype::table_size * sizeof(cctype::mask));

        rc[':'] = std::ctype_base::space; 
        return &rc[0];
    }
};

struct table_t
{
    std::string key;
    std::string first;
    std::string last;
    std::string rank;
    std::string additional;
};

int main() {
        std::string buf = "44:william:adama:commander:stuff\n33:luara:roslin:president:data\n";
        stringstream s(buf);
        s.imbue(std::locale(std::locale(), new colon_separated_only()));
        table_t t;
        std::vector<table_t> data;
        while ( s >> t.key >> t.first >> t.last >> t.rank >> t.additional )
        {
           data.push_back(t);
        }
        for(size_t i = 0 ; i < data.size() ; ++i )
        {
           cout << data[i].key <<" ";
           cout << data[i].first <<" "<<data[i].last <<" ";
           cout << data[i].rank <<" "<< data[i].additional << endl;
        }
        return 0;
}

输出:

44 william adama commander stuff
33 luara roslin president data

在线演示:http://ideone.com/JwZuk

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我在这里使用的技术在我对不同问题的另一个解决方案中有描述:

Elegant ways to count the frequency of words in a file