std::match_results::max_size

From cppreference.com
< cpp‎ | regex‎ | match results
size_type max_size() const;
(since C++11)

Returns the maximum number of submatches the match_results type is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest number of submatches.

Parameters

(none)

Return value

Maximum number of submatches

Exceptions

noexcept specification:  
noexcept
  

Complexity

Constant.