GCC 13.2 build error: possible dangling reference to a temporary

[kalibaer]

GCC 13.2 finds a possible dangling reference in include/cereal/details/polymorphic_impl.hpp line 204, 218, 231:

//.... error: possibly dangling reference to a temporary [-Werror=dangling-reference]
        auto const &mapping = lookup( baseInfo, typeid(Derived), [&](){ UNREGISTERED_POLYMORPHIC_CAST_EXCEPTION(save) } );
                    ^~~~~~~

[marcosbento]

I also ran into this issue.

After some investigation this now looks it might be a compiler bug i.e. a false positive. The return time of the lookup function is std::vector<PolymorphicCaster const *> const & and the value is a reference to a vector stored in the map StaticObject<PolymorphicCasters>::getInstance().map which is not temporary.

There are a couple of other projects that reported similar compiler regressions on GCC 13, for example 107532.

[jgreitemann]

After updating from GCC 13.2 to 14.1, the false-positive warning is indeed gone.

This issue can probably be closed as this confirms that this is a compiler regression?