c++11 is it safe to return an initializer_list value?

Question

I've this simple function:

initializer_list<int> f(){return {1,2,3};}

g++ gives a warning saying:

warning: returning temporary initializer_list does not extend the lifetime of the underlying array [-Winit-list-lifetime]

Is there any risk to return an {1, 2, 3}? Thanks for explanations!

I suggest to return a `std::vector` – Basile Starynkevitch Jun 25 '22 at 07:54 — Basile Starynkevitch, Jun 25 '22 at 07:54

score 4 · Accepted Answer · answered Jun 25 '22 at 07:54

An initializer_list behaves like a reference extending lifetime of a temporary (the temporary being the array).

Lifetime extension doesn't apply when returning references, so it doesn't apply here too. The compiler is right, the returned list is always dangling.

c++11 is it safe to return an initializer_list value?

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