[Bug c++/77542] __attribute__((warn_unused_result)) ignored on function template

[afenkart at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77542

--- Comment #2 from afenkart at gmail dot com ---
(In reply to Andrew Pinski from comment #1)
> Do you have a full example which shows the issue?
> In your case does ReturnValue  have a copy constructor?
> If so this is a dup of bug 38172.  Note C++17 defines [[nodiscard]] which
> should be used here instead really but it is only implemented in GCC 7.


It doesn't seem a duplicate of 38172, since the compiler emits a warning when
returning (non-trivial) struct. See attached example.