[Bug libstdc++/101203] Remove unnecessary empty check in std::function

[lutztonineubert at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101203

Toni Neubert  changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution|--- |WONTFIX

--- Comment #5 from Toni Neubert  ---
Improvement not possible for all environment.

[Bug libstdc++/101203] Remove unnecessary empty check in std::function

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101203

--- Comment #4 from Jonathan Wakely  ---
You can't use std::function at all in those environments.

[Bug libstdc++/101203] Remove unnecessary empty check in std::function

[lutztonineubert at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101203

--- Comment #3 from Toni Neubert  ---
Thank you Jonathan for your fast answer.
To sad but the shared library issue seems valid.

Can shared libraries exist is a freestanding environment (like a bare-metal
microcontroller running without OS)? So there could maybe an optimization for
some targets?

[Bug libstdc++/101203] Remove unnecessary empty check in std::function

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101203

--- Comment #2 from Jonathan Wakely  ---
We also can't guarantee that the address of the new function is unique across
shared libraries, making the test in _M_equal unreliable. The technique in
std::any has a fallback to using RTTI.

[Bug libstdc++/101203] Remove unnecessary empty check in std::function

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101203

--- Comment #1 from Jonathan Wakely  ---
PR 56551 uses a similar idea. It wouldn't be ABI compatible with existing code
though.