std::experi...::nullopt_t(3) C++ Standard Libary std::experi...::nullopt_t(3) NAME std::experimental::nullopt_t - std::experimental::nullopt_t Synopsis Defined in header <experimental/optional> struct nullopt_t; (library fundamentals TS) std::experimental::nullopt_t is an empty class type used to indicate op- tional type with uninitialized state. In particular, std::experimental::optional has a constructor with nullopt_t as a single argument, which creates an op- tional that does not contain a value. std::experimental::nullopt_t must be a LiteralType and cannot have a de- fault constructor. It must have a constexpr constructor that takes some implementation-de- fined literal type. Notes nullopt_t is not DefaultConstructible to support both op = {}; and op = nullopt; as the syntax for disengaging an optional object. A possible implementation of this class is struct nullopt_t { constexpr nullopt_t(int) {} }; See also nullopt an object of type nullopt_t (C++17) (constant) Category: * Noindexed pages http://cppreference.com 2024.06.10 std::experi...::nullopt_t(3)
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