[Bug c++/109247] [13 Regression] optional<T> o; o = {x}; wants to use explicit optional(U) constructor since r13-6765-ga226590fefb35ed6

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109247

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

           What    |Removed                     |Added
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           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=60027

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Patrick Palka from comment #4)
> Oops, this testcase from PR84849 might be strictly speaking invalid and GCC
> correct to reject.  Is this PR not invalid for the same reason?

Indeed, this seems to be a template form of CWG1228, and thus ill-formed.  But
it was accepted by GCC 9-12 and is also accepted by MSVC, EDG, and Clang, so I
wonder if the committee wants to adjust the standard to match the
implementations; I've asked.

But webkit should probably fix their code anyway, perhaps by changing 

 m_brush = {setPattern_pattern};

to

 m_brush = Brush{setPattern_pattern};