[Bug c++/84849] Ambiguous resolution of braze initializer list to a class with explicit constructors

[Bug c++/84849] Ambiguous resolution of braze initializer list to a class with explicit constructors

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=97220

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
PR 97220 looks similar and might be a dup of this bug.

[Bug c++/84849] [DR1228] Ambiguous resolution of braze initializer list to a class with explicit constructors

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Ambiguous resolution of     |[DR1228] Ambiguous
                   |braze initializer list to a |resolution of braze
                   |class with explicit         |initializer list to a class
                   |constructors                |with explicit constructors
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=cwg1228
             Status|ASSIGNED                    |SUSPENDED
           Assignee|mpolacek at gcc dot gnu.org        |unassigned at gcc dot gnu.org
                 CC|                            |jason at gcc dot gnu.org

--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> ---
I'm not marking this as a dup of PR60027 because of the specific case of
copy/move constructors, which cannot be constrained to avoid this problem.  The
patch in PR109247 fixes the first three testcases, which fall into that
category, but not the testcase in #5, which does not.

The testcase in #6 is unrelated; there is no "explicit".

Unassigning from Marek.

[Bug c++/84849] [DR1228] Ambiguous resolution of braze initializer list to a class with explicit constructors

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849

--- Comment #10 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to ensadc from comment #7)
> (In reply to Zhihao Yuan from comment #6)
> 
> I think this is a different bug. GCC thinks the implicitly-deleted move
> assignment operator `pair<int&>& pair<int&>::operator=(pair<int&>&&)` is a
> candidate for the assignment, which causes ambiguity with
> `operator=(value_type&&)` (where value_type = pair<int>). But as part of
> resolution of CWG 1402, [class.copy.assign] specifies that "A defaulted move
> assignment operator that is defined as deleted is ignored by overload
> resolution".

Incidentally, no: GCC mentions it, but considers it worse than any other
candidate.  The real ambiguity is with
operator=(const pair<int&>&), the implicitly-deleted *copy* assignment.  I
don't think this is a bug; if you disagree, please open another PR for it.

[Bug c++/84849] [DR1228] Ambiguous resolution of braze initializer list to a class with explicit constructors

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84849

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #11 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
DR1228 was closed as NAD.