Method gnuplot_version

source/matplot/backend/gnuplot.cpp:341–383

    }

    std::tuple<int, int, int> gnuplot::gnuplot_version() {
        static std::tuple<int, int, int> version{0, 0, 0};
        const bool dont_know_gnuplot_version_yet =
            version == std::tuple<int, int, int>({0, 0, 0});
        if (dont_know_gnuplot_version_yet) {
            std::string version_str =
                run_and_get_output("gnuplot --version 2>&1");
            std::string version_major = std::regex_replace(
                version_str,
                std::regex("[^]*gnuplot (\\d+)\\.\\d+ patchlevel \\d+ *"),
                "$1");
            std::string version_minor = std::regex_replace(
                version_str,
                std::regex("[^]*gnuplot \\d+\\.(\\d+) patchlevel \\d+ *"),
                "$1");
            std::string version_patch = std::regex_replace(
                version_str,
                std::regex("[^]*gnuplot \\d+\\.\\d+ patchlevel (\\d+) *"),
                "$1");
            try {
                std::get<0>(version) = std::stoi(version_major);
            } catch (...) {
                std::get<0>(version) = 0;
            }
            try {
                std::get<1>(version) = std::stoi(version_minor);
            } catch (...) {
                std::get<1>(version) = 0;
            }
            try {
                std::get<2>(version) = std::stoi(version_patch);
            } catch (...) {
                std::get<2>(version) = 0;
            }
            const bool still_dont_know_gnuplot_version =
                version == std::tuple<int, int, int>({0, 0, 0});
            if (still_dont_know_gnuplot_version) {
                // assume it's 5.2.6 by convention
                version = std::tuple<int, int, int>({5, 2, 6});
            }
        }
        return version;
    }

    bool gnuplot::terminal_has_title_option(const std::string &t) {
        SV_CONSTEXPR std::string_view whitelist[] = {