std::match_results::empty

From cppreference.com
< cpplrm; | regexlrm; | match results
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)