c++ string去除首尾 空格、 、 、

    string s = "    test ";
    size_t n = s.find_last_not_of(" 
	");
    if (n != string::npos){
        s.erase(n + 1, s.size() - n);
    }
    n = s.find_first_not_of(" 
	");
    if (n != string::npos){
        s.erase(0, n);
    }

string trimstr(string s){
  size_t n = s.find_last_not_of(" 
	");
    if (n != string::npos){
        s.erase(n + 1, s.size() - n);
    }
    n = s.find_first_not_of(" 
	");
    if (n != string::npos){
        s.erase(0, n);
    }
    return s;
}