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.
Parameters
- first, last
- Forward iterators to the initial and final positions in a sequence of characters. The range used is [first,last), which includes all the characters between first and last, including the character pointed by first but not the character pointed by last.
Return value
The string representing the corresponding named collating element, or an empty string if it does not correspond to a collating element.