#include <random>
#include <iostream>

int main()
{
    auto n = 9;
    auto rnd = std::random_device{};
    auto gen = std::mt19937_64{rnd()};
    auto dis = std::uniform_real_distribution<double>{-0.1, 0.2};
    auto res = std::vector<double>{};
    std::generate_n(
        std::inserter(res, std::end(res)),
        n,
        [&](){ return dis(gen); }); 

    for (const auto& elem: res)
    {
        std::cout << elem << '\n';
    }
}