[Bug c++/58181] New: A bug in lambda expression

[fimbul77 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58181

            Bug ID: 58181
           Summary: A bug in lambda expression
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fimbul77 at gmail dot com

Following the code:

#include <tuple>
#include <cassert>

int main()
{
    assert(std::get<0>(
        []() {
            int x = 0;
            return std::forward_as_tuple([=]() -> int {
                return x;
            });
        }()
    )() == 0);
}

The assertion fails in gcc.(but only gcc4.6.4 succeed it)
But I think it must be success.
The variable x in [=]() -> int { return x; } should not garbage.
It may be a lambda expression bug.

Wandbox
http://melpon.org/wandbox/permlink/MRhUXl888hCZAQcx