[Bug c++/123659] New: [reflection] Cannot splice a pack of type reflections

[boris.staletic at protonmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123659

            Bug ID: 123659
           Summary: [reflection] Cannot splice a pack of type reflections
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: boris.staletic at protonmail dot com
  Target Milestone: ---

Created attachment 63374
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63374&action=edit
Preprocessed snippet

The following snippet:

```
#include <meta>
#include <array>

template<size_t...Is>
void test1() {
    static constexpr std::meta::info types[]{^^int};
    [](typename[:types[Is]:]... args) {};
}
```

Errors with

```
3.cpp: In function 'void test1()':
3.cpp:7:33: error: expansion pattern '[: types[Is] :]' contains no parameter
packs [-Wtemplate-body]
    7 |     [](typename[:types[Is]:]... args) {};
      |                                 ^~~~
Compiler returned: 1
```