problem in running c++ 17 code

With these two commands sudo apt-get update sudo apt install build-essential I install c++ compiler and it has GCC/g++ version 10,than I install VS-Code and install two extensions code-runner and c++ extension by Microsoft, it runs this code

#include <iostream>
using namespace std;
int main(){
    cout<<"hello world";
    return 0;
}

But not this c++17 specific code

#include <array>
#include <iostream>
#include <string_view>
#include <tuple>
#include <type_traits>

namespace a::b::c
{
    inline constexpr std::string_view str{ "hello" };
}

template <class... T>
std::tuple<std::size_t, std::common_type_t<T...>> sum(T... args)
{
    return { sizeof...(T), (args + ...) };
}

int main()
{
    auto [iNumbers, iSum]{ sum(1, 2, 3) };
    std::cout << a::b::c::str << ' ' << iNumbers << ' ' << iSum << '\n';

    std::array arr{ 1, 2, 3 };

    std::cout << std::size(arr) << '\n';

    return 0;
}

kindly help me to solve this issue Thanks in anticipation