std::optional specialization for reference types

c++ c++11 stl optional boost-optional
Tomilov Anatoliy picture Tomilov Anatoliy · Nov 11, 2014 · Viewed 13.3k times · Source

Why std::optional (std::experimental::optional in libc++ at the moment) does not have specialization for reference types (compared with boost::optional)?

I think it would be very useful option.

Is there some object with reference to maybe already existing object semantics in STL?

Answer

Nevin picture Nevin · Nov 12, 2014

When n3406 (revision #2 of the proposal) was discussed, some committee members were uncomfortable with optional references. In n3527 (revision #3), the authors decided to make optional references an auxiliary proposal, to increase the chances of getting optional values approved and put into what became C++14. While optional didn't quite make it into C++14 for various other reasons, the committee did not reject optional references and is free to add optional references in the future should someone propose it.

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