[Bug c++/101243] Coroutine lambda capture is destroyed twice

["nathan at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101243

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nathan at gcc dot gnu.org

--- Comment #3 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
Created attachment 51358
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51358&action=edit
move-only type

Modified to make the capture a move-only type

devvm1702:323>./cc1plus -std=c++20 pr.ii -quiet              
pr.cc: In function 'task f()':
pr.cc:73:1: warning: 'f()::_Z1fv.Frame' has a field
'f()::_Z1fv.Frame::D.48642_2_3' whose type has no linkage [-Wsubobject-linkage]
In file included from
/data/users/nathans/tools/include/c++/10.1.1/functional:59,
                 from pr.cc:2:
/data/users/nathans/tools/include/c++/10.1.1/bits/std_function.h: In
instantiation of 'static void
std::_Function_base::_Base_manager<_Functor>::_M_clone(std::_Any_data&, const
std::_Any_data&, std::false_type) [with _Functor =
f(f()::_Z1fv.Frame*)::<lambda()>; std::false_type =
std::integral_constant<bool, false>]':
/data/users/nathans/tools/include/c++/10.1.1/bits/std_function.h:196:16:  
required from 'static bool
std::_Function_base::_Base_manager<_Functor>::_M_manager(std::_Any_data&, const
std::_Any_data&, std::_Manager_operation) [with _Functor =
f(f()::_Z1fv.Frame*)::<lambda()>]'
/data/users/nathans/tools/include/c++/10.1.1/bits/std_function.h:283:23:  
required from 'static bool std::_Function_handler<_Res(_ArgTypes ...),
_Functor>::_M_manager(std::_Any_data&, const std::_Any_data&,
std::_Manager_operation) [with _Res = void; _Functor =
f(f()::_Z1fv.Frame*)::<lambda()>; _ArgTypes = {}]'
/data/users/nathans/tools/include/c++/10.1.1/bits/std_function.h:611:19:  
required from 'std::function<_Res(_ArgTypes ...)>::function(_Functor) [with
_Functor = f(f()::_Z1fv.Frame*)::<lambda()>; <template-parameter-2-2> = void;
<template-parameter-2-3> = void; _Res = void; _ArgTypes = {}]'
pr.cc:71:13:   required from here
/data/users/nathans/tools/include/c++/10.1.1/bits/std_function.h:161:13: error:
use of deleted function 'f(f()::_Z1fv.Frame*)::<lambda()>::<lambda>(const
f(f()::_Z1fv.Frame*)::<lambda()>&)'
  161 |             new _Functor(*__source._M_access<const _Functor*>());
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pr.cc:71:22: note: 'f(f()::_Z1fv.Frame*)::<lambda()>::<lambda>(const
f(f()::_Z1fv.Frame*)::<lambda()>&)' is implicitly deleted because the default
definition would be ill-formed:
pr.cc:71:22: error: use of deleted function 'FOO::FOO(const FOO&)'
pr.cc:59:3: note: declared here