[Bug libstdc++/106067] [13/14/15/16 Regression] Error on implicit conversion to std::function: 'static constexpr bool std::_Function_handler<...>...' used before its definition

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106067

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|redi at gcc dot gnu.org            |unassigned at gcc dot gnu.org
             Status|ASSIGNED                    |NEW

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to 3440910457 from comment #4)
> This bug is still exists in GCC 15.2

Yes, and GCC 16 (as it says in the summary).

> The bug may be not related to the libstdc++ <functional>. It is maybe
> actually related to the instantiation sequence of the template function.
> 
> The following code started failing on GCC 14.1 (also fails on GCC 15.2)

This reduced example started to fail with r14-4793. Since the similar error in
std::function already happened before that change, I think it's a different
problem. That should be reported separately as a g++ regression so I created
Bug 124389.