c++ regex helpers

Question

I've created 2 helpers for std::regex.

The first helper match fills the given std::vector<std::pair<std::string, std::size_t>> with the first match with all subgroup matches and their positions. match_all builds on match and sets the given std::vector<std::vector<std::pair<std::string, std::size_t>>> to all the matches in the text.

I would like to maybe in the future use CTRE instead of std::regex but for now this is what I have:

using match_result = std::vector<std::pair<std::string, std::size_t>>;
using match_all_result = std::vector<match_result>;

std::size_t match(const std::regex& regex, const std::string& input, match_result* result) {
        std::size_t total{ 0 };
        std::smatch m;

        if (std::regex_search(input, m, regex)) {
            total = m.size();

            if (result != nullptr) {
                std::size_t startPos{};
                std::string original{};

                for (size_t i = 0; i < m.size(); i++) {
                    const std::string dataMatch{ m[i] };
                    std::size_t pos{};

                    if (i == 0) { //full match                        
                        startPos = pos = m.position();
                        original = dataMatch;
                    }
                    else {
                        pos = startPos;
                        if (dataMatch != original)
                            pos += original.find(dataMatch);
                    }

                    result->emplace_back(dataMatch, pos);
                }
            }
        }

        return total;
    }

    std::size_t match_all(const std::regex& regex, std::string input, match_all_result* result) {
        match_result m{};
        std::size_t positionFix{};
        auto first{ true };
        std::size_t total{};

        while (const auto t = match(regex, input, &m)) {
            total += t;
            const auto sumLP = m[0].first.size() + m[0].second;

            if (first) {
                positionFix = sumLP;
                first = false;
            }
            else {
                if (result) {
                    for (auto& [m1, p1] : m) {
                        p1 += positionFix;
                    }
                }
                positionFix += sumLP;
            }

            //input = input.c_str() + (sumLP);
            input = input.substr(sumLP);

            if (result) {
                result->push_back(m);
                m.clear();
            }
        }


        return total;
    }

You can see the code running here: https://gcc.godbolt.org/z/wHRZET

NOTE: fixed the description as what I had described what my code did previously. It now does not return a vector but expects a pointer to a vector to be passed.