The build with clang 19.1.0 fails in c++20 mode.

[lemourin]

Compiler log:

.../include/sqlite_orm/sqlite_orm.h:1321:20: error: cannot initialize return object of type 'size_t' (aka 'unsigned long') with an lvalue of type '<dependent type>'
 1321 |             return Idx...[Pos];

Interestingly enough, clang still defines __cpp_pack_indexing to 202311L even though I compile with -std=c++20 which is probably incorrect on the compiler side.

[theo-dep]

I have a same issue using clang-tidy 19.1.1 on Ubuntu and -std=c++23.

This signature works (obviously):

template<size_t Pos, size_t... Idx>
SQLITE_ORM_CONSTEVAL auto index_sequence_value_at(std::index_sequence<Idx...>);

[Arteiimis]

any plan to fix this?

[fnc12]

@Arteiimis yeah. I put it on the public board. Will be fixed soon

[trueqbit]

Who would have known that clang enables pack indexing in all language modes just like that...
Yet clang's real problem is that its expression evaluation is wrong. Thx @theo-dep for pointing out that a return type of auto works.
The second weirdness is the compiler warning, which doesn't make any sense. Either unconditionally supported or not.

@Arteiimis It would be nice if you would improve your problem report to the llvm project and report two different things with a clear example similar to this one.

[Arteiimis]

Who would have known that clang enables pack indexing in all language modes just like that... Yet clang's real problem is that its expression evaluation is wrong. Thx @theo-dep for pointing out that a return type of auto works. The second weirdness is the compiler warning, which doesn't make any sense. Either unconditionally supported or not.

@Arteiimis It would be nice if you would improve your problem report to the llvm project and report two different things with a clear example similar to this one.

llvm/llvm-project#123074 (comment)

believe this is a clang bug, godbolt links in the comment above.

[Arteiimis]

llvm/llvm-project#121405