https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59655
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |diagnostic
Last reconfirmed|2017-10-01 00:00:00 |2018-5-3
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=80916
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
A smaller testcase:
template<typename T> struct trait { static constexpr bool value = false; };
struct thread {
template<typename T, typename... U>
thread(T t)
{
static_assert(trait<T>::value, "trait");
foo(t);
}
template<typename T> void foo(T) { return; }
};
int main()
{
thread t([](int) { });
}
used.cc: In instantiation of 'thread::thread(T) [with T =
main()::<lambda(int)>; U = {}]':
used.cc:17:23: required from here
used.cc:7:21: error: static assertion failed: trait
static_assert(trait<T>::value, "trait");
^~~~~~~~
used.cc:12:29: error: 'void thread::foo(T) [with T = main()::<lambda(int)>]',
declared using local type 'main()::<lambda(int)>', is used but never defined
[-fpermissive]
template<typename T> void foo(T) { return; }
^~~
used.cc:12:29: warning: 'void thread::foo(T) [with T = main()::<lambda(int)>]'
used but never defined
