[Bug c++/106291] New: Literal class can appear in the constant-expression of a declaration of a bit-field

[Bug c++/106291] New: Literal class can appear in the constant-expression of a declaration of a bit-field

[xmh970252187 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106291

            Bug ID: 106291
           Summary: Literal class can appear in the constant-expression of
                    a declaration of a bit-field
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xmh970252187 at gmail dot com
  Target Milestone: ---

struct A{
    constexpr operator int(){
        return 8;
    }
};
struct B{
    int a:A{};
};

GCC rejects this example, with a diagnosis that
> error: width of bit-field 'a' has non-integral type 'A'

[expr.const] p9 explicitly permit this case. 
> If an expression of literal class type is used in a context where an integral constant expression is required, then that expression is contextually implicitly converted ([conv]) to an integral or unscoped enumeration type and the selected conversion function shall be constexpr.

Clang accepts this example

[Bug c++/106291] Literal class can appear in the constant-expression of a declaration of a bit-field

[xmh970252187 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106291

--- Comment #1 from jim x <xmh970252187 at gmail dot com> ---
https://godbolt.org/z/x5hPe5qoP

[Bug c++/106291] Literal class can appear in the constant-expression of a declaration of a bit-field

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106291

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 83929.

*** This bug has been marked as a duplicate of bug 83929 ***