arene::base::nullopt_t Class Reference

Empty class type used to indicate that arene::base::optional does not contain a value. More...

Public Member Functions
constexpr	nullopt_t (detail::unspecified_t) noexcept
	constructor for nullopt_t

Detailed Description

Empty class type used to indicate that arene::base::optional does not contain a value.

Note

arene::base::nullopt_t is a non-aggregate type, has no default constructor, and no initializer-list constructor.

Constructor & Destructor Documentation

nullopt_t()

arene::base::nullopt_t::nullopt_t ( detail::unspecified_t )

inlineexplicitconstexprnoexcept

constructor for nullopt_t

Note

This constructor exists to support both op = {}; and op = nullopt; as the syntax for indicating that an arene::base::optional does not contain a value.

see ISO/IEC JTC1 SC22 WG21 N3672 for more nuanced discussion of the op = {}; syntax.

In arene-base version 3.47.1 and prior, this arene::base::nullopt_t was erroneously default constructible.

The type of the parameter to this constructor is unspecified. Users should rely on arene::base::nullopt for an instance of a arene::base::nullopt_t rather than constructing an instance of arene::base::nullopt_t directly.

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The documentation for this class was generated from the following file:

• arene/base/optional/optional.hpp