https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
Jason Merrill changed:
What|Removed |Added
Ever confirmed|0 |1
Status|UNCONFIRMED
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #7 from Tomasz Kamiński ---
Or in other words, I believe my example is equivalent to implementation of
optional,
where we have:
union {
T val;
};
And then call:
new(static_cast(addressof(val))) T(...);
It is just version were T
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #6 from Tomasz Kamiński ---
I believed that `_member` being active after new should directly fall from the
definition of active member in https://eel.is/c++draft/class.union#general-2:
> In a union, a non-static data member is active
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #5 from Jason Merrill ---
The intent of the patch was to support
new (&union_.member) T
syntax like
union_.member = T()
for setting the active member, as in
https://eel.is/c++draft/class.union#general-example-3
but adding the li
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #4 from Tomasz Kamiński ---
Hi, the original example works, but when I start to add library fluff, I get
the same error. I mean cases like:
// passing address to actual member
new(&arr) T[3];
new(std::addressof(arr)) T[3]; // Disable
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #3 from Jason Merrill ---
Created attachment 61891
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61891&action=edit
fix
Let me know how this works for you.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
--- Comment #2 from Tomasz Kamiński ---
That is indeed very surprising, as it would mean that if I have:
```
struct S {
union {
int x;
};
};
constexpr S test()
{
S s;
new(&s.x) int;
is_active_member(s.x); // this is false
}
```
On
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121068
Jason Merrill changed:
What|Removed |Added
CC||jason at gcc dot gnu.org
--- Comment #1
