#include<random>
std::default_random_engine generator;
std::uniform_int_distribution<int> distribution(1,6);
int dice_roll = distribution(generator);  //between [1,6]

#include<random>
std::default_random_engine generator;
std::uniform_real_distribution<double> distribution(0.0,2.0);
double random = distribution(generator);//between [0.0,2.0)

#include <iostream>
#include "xsimd/xsimd.hpp"

namespace xs = xsimd;

int main(int argc, char* argv[])
{
    xs::batch<double, xs::avx2> a(1.5, 2.5, 3.5, 4.5);
    xs::batch<double, xs::avx2> b(2.5, 3.5, 4.5, 5.5);
    auto mean = (a + b) / 2;
    std::cout << mean << std::endl;
    return 0;
}

#include <cstddef>
#include <vector>
#include "xsimd/xsimd.hpp"

namespace xs = xsimd;
using vector_type = std::vector<double, xsimd::aligned_allocator<double>>;

void mean(const vector_type& a, const vector_type& b, vector_type& res)
{
    std::size_t size = a.size();
    constexpr std::size_t simd_size = xsimd::simd_type<double>::size;
    std::size_t vec_size = size - size % simd_size;

    for(std::size_t i = 0; i < vec_size; i += simd_size)
    {
        auto ba = xs::load_aligned(&a[i]);
        auto bb = xs::load_aligned(&b[i]);
        auto bres = (ba + bb) / 2.;
        bres.store_aligned(&res[i]);
    }
    for(std::size_t i = vec_size; i < size; ++i)
    {
        res[i] = (a[i] + b[i]) / 2.;
    }
}

#include <cstddef>
#include <vector>
#include "xsimd/xsimd.hpp"
#include "xsimd/stl/algorithms.hpp"

namespace xs = xsimd;
using vector_type = std::vector<double, xsimd::aligned_allocator<double>>;

void mean(const vector_type& a, const vector_type& b, vector_type& res)
{
    xsimd::transform(a.begin(), a.end(), b.begin(), res.begin(),
                     [](const auto& x, const auto& y) { (x + y) / 2.; });
}