[Bug c/116302] transparent union does not work with {integral type, bitfield struct}

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116302

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

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

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is not how you use transparent_union ...

For this to work, you should do :
```
opflags_t antiop(opflags_t op)
{
    return (op.v = ~op.v), op;
}

```

`transparent union` is ONLY about argument passing and nothing else.

This is documented as such too.
From
https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/Common-Type-Attributes.html#index-transparent_005funion-type-attribute
:

This attribute, attached to a union type definition, indicates that any
function parameter having that union type causes calls to that function to be
treated in a special way.