std::match_results<BidirIt,Alloc>::max_size
Min standard notice:
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.
# Declarations
size_type max_size() const noexcept;
(since C++11)
# Return value
Maximum number of submatches.