c++ std::execution::par,std::execution::par

#include <algorithm>
#include <chrono>
#include <cstdint>
#include <execution>
#include <iostream>
#include <random>
#include <vector>

std::random_device rd;
std::mt19937_64 mt{rd()};

template <typename T>
T gen_random(T min, T max)
{
    std::uniform_int_distribution<T> uid(min, max);
    return uid(mt);
}

void vector_sort_execution_par(const int &len)
{
    std::vector<std::uint32_t> vec;
    for (int i = 0; i < len; i++)
    {
        vec.push_back(gen_random<std::uint32_t>(0, UINT32_MAX));
    }

    for (auto i : vec)
    {
        std::cout << i << "\t";
    }
    std::cout << std::endl;

    std::sort(std::execution::par, vec.begin(), vec.end());
    std::cout << "After sort parallel:" << std::endl;
    for (auto i : vec)
    {
        std::cout << i << "\t";
    }
    std::cout << std::endl;
}

void vector_transformer_execution_par()
{
    std::vector<int> vec1 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    std::vector<int> vec2(10);
    std::transform(std::execution::par, vec1.begin(), vec1.end(), vec2.begin(), [](int x)
                   { return x * x; });
    for (auto i : vec2)
    {
        std::cout << i << "\t";
    }
    std::cout << std::endl;
}

void vector_execution_par_unseq(const int &len)
{
    std::vector<std::uint32_t> vec;
    for (int i = 0; i < len; i++)
    {
        std::uint32_t temp=gen_random<std::uint32_t>(0, UINT32_MAX);
        vec.push_back(temp); 
    }
    std::for_each(std::execution::par_unseq, vec.begin(), vec.end(), [](std::uint32_t x)
                  { std::cout << x << "\t"; });
    std::cout << std::endl;
}

int main(int args, char **argv)
{
    vector_execution_par_unseq(atoi(argv[1]));
}