https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126561
Bug ID: 126561
Summary: [c++26] typename-splice pseudo-destructor-name
rejected for scalar types (accepted for class types)
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: 121539739 at qq dot com
Target Milestone: ---
Per [expr.prim.id.unqual], an unqualified-id can be `~ type-name` or
`~ computed-type-specifier`, and [dcl.type.simple] lists three
computed-type-specifiers: decltype-specifier, pack-index-specifier,
and splice-type-specifier. For a scalar type this forms a
pseudo-destructor name.
GCC accepts the typename-splice form when the object is of CLASS
type, but rejects it for scalar types, where only a plain type-name
works:
```cpp
// class type: accepted
struct S {};
void c1(S s) { s.~typename [:^^S:](); } // OK
// scalar type: rejected
void s1(int x) { x.~typename [:^^int:](); }
// error: expected identifier before 'typename'
// plain type-name pseudo-destructor works
using I = int;
void s0(int x) { x.~I(); } // OK
```
Command line: g++ -std=c++26 -freflection
Expected: s1 should be accepted.
