任意定界符/转义字符处理的最佳算法是什么？

void smartSplit(string const& text, char delim, char esc, vector& tokens)
{
enum State { NORMAL, IN_ESC };
State state = NORMAL;
string frag;

    for (size_t i = 0; i<text.length(); ++i)    {        char c = text[i];        switch (state)        {        case NORMAL: if (c == delim) {     if (!frag.empty())         tokens.push_back(frag);     frag.clear(); } else if (c == esc)     state = IN_ESC; else     frag.append(1, c); break;        case IN_ESC: frag.append(1, c); state = NORMAL; break;        }    }    if (!frag.empty())        tokens.push_back(frag);}