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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/109801] -Wmaybe-uninitialized warning with
 -O1 on move constructor
Date: Thu, 25 May 2023 18:24:06 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109801

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Scott Zhong from comment #4)
> The move constructor "steals" resources rather than make copies of them, =
and
> leave the argument in some valid but otherwise indeterminate state. It is
> reasonable that size_ is not initialized in the context of a move
> constructor.
>=20
> If you define body to the constructor and destructor for the class list, =
the
> warning goes away, which has nothing to do with size_ being initialized or
> not.
>=20
> template <typename T>
> class list
> {
> public:
>     list() {}
>     ~list() {}
> };

Because if you don't have the define then the calls might clobber some other
memory ...=