problem ze zrozumieniem regex_search

#include <stdio.h>
#include <regex>
#include <iostream>
#include <string>

int main()
{
    std::regex pattern("^(abc)+.xz");
    std::string text {"abc.xz"};
    std::smatch s;
    if(std::regex_search(text,s,pattern)) {
        std::cout << "found seq" << std::endl;
        for(auto x: s)
            std::cout << x << std::endl;
    }

    return 0;
}

std::regex pattern("(abc)");
std::string text {"abc"};

#include <stdio.h>
#include <regex>
#include <iostream>
#include <string>
#include <vector>

std::vector<std::string> getWords(const std::string& text)
{
    std::vector<std::string> output;
    std::regex pattern("[^\\s*]*");
    std::smatch s;
    if(regex_search(text,s,pattern))
        for(const auto& x : s)
            output.push_back(x);
    
    return output;
}

int main()
{
    std::vector<std::string> vec = getWords("Ala ma kota\ni psa");
    for(const auto& x: vec)
        std::cout << x << std::endl;

    return 0;
}

std::vector<std::string> getWords(const std::string& text)
{
    std::vector<std::string> output;
    std::regex pattern("[^\\s]*");
    std::transform(
        std::sregex_iterator{begin(text), end(text), pattern},
        std::sregex_iterator{}, std::back_inserter(output),
        [](const auto& match) {return match.str();});
    return output;
}

std::vector<std::string> getWords(const std::string& text)
{
    using std::regex_constants::match_not_null;
    std::vector<std::string> output;
    std::regex pattern("[^\\s]*");
    std::smatch s;
    while(regex_search(s.ready() ? s[0].second : begin(text), end(text), s, pattern, match_not_null)) {
        output.push_back(s.str());
    }
    return output;
}

std::vector<std::string> getWords(const std::string& text)
{
    std::vector<std::string> output;
    string tekst = text;
    const regex pattern("(\\s)");
    tekst = regex_replace(tekst, pattern, " ");
    const regex spaces("([[:space:]]+)");
    tekst = regex_replace(tekst, spaces, " ");
    output.push_back(tekst);
    return output;
}