std::match_results<BidirIt,Alloc>::empty

bool empty() const;
 (since C++11)
(until C++20) 
[[nodiscard]] bool empty() const;
 (since C++20)

Checks whether the match was successful.

Parameters

(none).

Return value

size() == 0 (false if *this represents the result of a successful match, true otherwise).

Exceptions

(none).

Complexity

Constant.

See also

returns the number of matches in a fully-established result state
(public member function)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/regex/match_results/empty