public member function
<regex>
std::regex_traits::lookup_collatename
template <class ForwardIterator> string_type lookup_collatename (ForwardIterator first, ForwardIterator last) const;
Return collate name equivalent
Returns a string representing the named collating element that corresponds to the character sequence between first and last, or an empty string (if the character sequence is not a valid collating element).
This function is called when a potential named collating element is encountered in a regular expression.
参数
- first, last
- 指向字符序列中初始和最终位置的前向迭代器。使用的范围是[first,last)，其中包括first和last之间的所有字符，包括first指向的字符，但不包括last指向的字符。
返回值
The string representing the corresponding named collating element, or an empty string if it does not correspond to a collating element.