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Subject: [Bug c++/772] Statement expressions issues
Date: Wed, 20 Jan 2021 09:37:20 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D772

--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Ed Smith-Rowland from comment #14)
> I wonder what the relationship of these expression statements are to lamb=
das.
>=20
> Is ({int _a =3D (a), _b =3D (b); _a > _b ? _a : _b; })
> equivalent to
> [](){int _a =3D (a), _b =3D (b); _a > _b ? _a : return _b; }}
>=20
> Can expression statements change enclosing scope variables?  It seems like
> they could.  The lambda may need to be mutable.
>=20
> Maybe these could route to the lambda code.
>=20
> Just an idle thought.

There are substantial differences.
E.g. one can do ({ return 1; }), with lambdas it means something different,
or ({ break; }) or ({ continue; }).=