std::match_results

template<
    class BidirIt,
    class Alloc = std::allocator<std::sub_match<BidirIt>>
> class match_results;

namespace pmr {
    template <class BidirIt>
    using match_results = std::match_results<BidirIt,
                              std::pmr::polymorphic_allocator<
                                  std::sub_match<BidirIt>>>;
}

The class template std::match_results holds a collection of character sequences that represent the result of a regular expression match.

This is a specialized allocator-aware container. It can only be default created, obtained from std::regex_iterator, or modified by std::regex_search or std::regex_match. Because std::match_results holds std::sub_matches, each of which is a pair of iterators into the original character sequence that was matched, it's undefined behavior to examine std::match_results if the original character sequence was destroyed or iterators to it were invalidated for other reasons.

The first sub_match (index 0) contained in a match_result always represents the full match within a target sequence made by a regex, and subsequent sub_matches represent sub-expression matches corresponding in sequence to the left parenthesis delimiting the sub-expression in the regex.

std::match_results meets the requirements of a constant AllocatorAwareContainer and of a constant SequenceContainer, except that the semantics of comparison functions are different from those required for a container.

Type requirements

Specializations

Several specializations for common character sequence types are provided:

Member types

Member functions

Non-member functions