[Bug c++/67768] New: Second and subsequent captured variable in variadic template unpaking are default constructed

["dtyazskwindows7 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67768

            Bug ID: 67768
           Summary: Second and subsequent captured variable in variadic
                    template unpaking are default constructed
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dtyazskwindows7 at gmail dot com
  Target Milestone: ---

When you compile and run the following code in gcc6.0
=================================
#include<iostream>
#include<utility>
#include<tuple>

template<std::size_t I,class T>T echo(T v)
{
    return v;
}
template<std::size_t... Is>auto run(std::index_sequence<Is...>)
{
    int x = 10;
    return std::make_tuple(echo<Is>([y=x](){std::cout<<y<<std::endl;})...);
}

int main()
{
    auto v = run(std::make_index_sequence<3>());
    std::get<0>(v)();
    std::get<1>(v)();
    std::get<2>(v)();
}
========================================
output is as follows:
10
0
0