Why Doesn\'t `std::optional` Support Reference Types?

Optional References: Absence in std::optional

Unlike Boost's optional class, which supports reference types, the Standard Library's std::optional lacks this functionality. This omission has prompted inquiries into the reasoning behind this decision.

Lack of Specialization

When std::optional was initially proposed as std::experimental::optional in libc , the committee members voiced concerns regarding optional references. Subsequently, in the third revision of the proposal (n3527), the authors opted to make optional references an auxiliary proposal to enhance the likelihood of optional values being approved and incorporated into C 14.

Future Prospects

While optional references did not make it into C 14 for other reasons, the committee did not reject them outright. They remain open to the possibility of including optional references in future C standards if a formal proposal is presented.

Alternative Solutions

In the meantime, developers can consider alternative solutions such as custom object wrappers or using the boost::optional library, which provides the functionality for reference types.

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