Address a constexpr template point of instantiation issue

...that hits at least when building with Clang and --with-latest-c++ against
recent libc++ or MSVC standard library (where C++20 and esp. C++23 made more and
more class template member functions constexpr).  My understanding is that there
is some leeway at what point a compiler should instantiate such function
specializations, and Clang decides to instantiate constexpr ones early (cf.
<https://github.com/llvm/llvm-project/commit/242ad89a15d5466d166d47978bfff983d40ab511>
"C++11 half of r147023: In C++11, additionally eagerly instantiate:" and its "Do
not defer instantiations of constexpr functions" comment, and the discussion at
<https://discourse.llvm.org/t/point-of-instantiation-of-constexpr-function-template/65129>).

> In file included from sw/source/core/access/acccell.cxx:20:
> In file included from include/sal/log.hxx:20:
> In file included from ~/llvm/inst/bin/../include/c++/v1/sstream:186:
> In file included from ~/llvm/inst/bin/../include/c++/v1/istream:165:
> In file included from ~/llvm/inst/bin/../include/c++/v1/ostream:168:
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:47:19: error: invalid application of 'sizeof' to an incomplete type 'FndLine_'
>     static_assert(sizeof(_Tp) >= 0, "cannot delete an incomplete type");
>                   ^~~~~~~~~~~
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:281:7: note: in instantiation of member function 'std::default_delete<FndLine_>::operator()' requested here
>       __ptr_.second()(__tmp);
>       ^
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:247:75: note: in instantiation of member function 'std::unique_ptr<FndLine_>::reset' requested here
>   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX23 ~unique_ptr() { reset(); }
>                                                                           ^
> ~/llvm/inst/bin/../include/c++/v1/__memory/construct_at.h:64:13: note: in instantiation of member function 'std::unique_ptr<FndLine_>::~unique_ptr' requested here
>     __loc->~_Tp();
>             ^
> ~/llvm/inst/bin/../include/c++/v1/__memory/construct_at.h:89:12: note: in instantiation of function template specialization 'std::__destroy_at<std::unique_ptr<FndLine_>, 0>' requested here
>     _VSTD::__destroy_at(__loc);
>            ^
> ~/llvm/inst/bin/../include/c++/v1/__memory/allocator_traits.h:317:16: note: in instantiation of function template specialization 'std::destroy_at<std::unique_ptr<FndLine_>, 0>' requested here
>         _VSTD::destroy_at(__p);
>                ^
> ~/llvm/inst/bin/../include/c++/v1/vector:834:25: note: in instantiation of function template specialization 'std::allocator_traits<std::allocator<std::unique_ptr<FndLine_>>>::destroy<std::unique_ptr<FndLine_>, void, void>' requested here
>         __alloc_traits::destroy(__alloc(), std::__to_address(--__soon_to_be_end));
>                         ^
> ~/llvm/inst/bin/../include/c++/v1/vector:828:29: note: in instantiation of member function 'std::vector<std::unique_ptr<FndLine_>>::__base_destruct_at_end' requested here
>   void __clear() _NOEXCEPT {__base_destruct_at_end(this->__begin_);}
>                             ^
> ~/llvm/inst/bin/../include/c++/v1/vector:433:9: note: in instantiation of member function 'std::vector<std::unique_ptr<FndLine_>>::__clear' requested here
>         __clear();
>         ^
> sw/inc/tblsel.hxx:170:5: note: in instantiation of member function 'std::vector<std::unique_ptr<FndLine_>>::~vector' requested here
>     FndBox_( SwTableBox* pB, FndLine_* pFL ) :
>     ^
> sw/inc/tblsel.hxx:152:7: note: forward declaration of 'FndLine_'
> class FndLine_;
>       ^

Change-Id: Ia088547c6463a55f48bb4c4ca5107b3bf9472ff1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/141820
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

0 files changed, 0 insertions, 0 deletions