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From: "dilyan.palauzov at aegee dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/114220] False positive warning: possibly dangling reference
 to a temporary [-Wdangling-reference]
Date: Sun, 03 Mar 2024 10:30:26 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114220

--- Comment #3 from =D0=94=D0=B8=D0=BB=D1=8F=D0=BD =D0=9F=D0=B0=D0=BB=D0=B0=
=D1=83=D0=B7=D0=BE=D0=B2 <dilyan.palauzov at aegee dot org> ---
> The warning is designed this way explictly because you are returning a re=
ference and taking a reference as an argument and in the case of b2, the te=
mpory is `std::string("u")` .

> In GCC 14+ (since r14-9263-gc7607c4cf18986), you can add [[gnu::no_dangli=
ng]] to the z2 function definition to mark it as not returning a dangling r=
eference (from the arguments). and the warning goes away.

If the declaration and definitions are in different files, do I have to add
[[gnu::no_dangling]] only to the function declaration ?

That said, is the warning triggered only based on the function declaration
(accepting as parameter a reference to temporary and returning a reference),
when on the function invocation the parameter is indeed a reference to a
temporary?=