Optional values

Collaboration diagram for Optional values:

Classes
struct	std::experimental::fundamentals_v1::_Has_addressof< _Tp >
class	std::experimental::fundamentals_v1::_Optional_base< _Tp, _ShouldProvideDestructor >
class	std::experimental::fundamentals_v1::_Optional_base< _Tp, false >
class	std::experimental::fundamentals_v1::bad_optional_access
struct	std::experimental::fundamentals_v1::in_place_t
struct	std::experimental::fundamentals_v1::nullopt_t
class	std::experimental::fundamentals_v1::optional< _Tp >

Macros
#define	__cpp_lib_experimental_optional

Typedefs
template<typename _Tp , typename _Up >
using	std::experimental::fundamentals_v1::__assigns_from_optional = __or_< is_assignable< _Tp &, const optional< _Up > & >, is_assignable< _Tp &, optional< _Up > & >, is_assignable< _Tp &, const optional< _Up > && >, is_assignable< _Tp &, optional< _Up > && > >
template<typename _Tp , typename _Up >
using	std::experimental::fundamentals_v1::__converts_from_optional = __or_< is_constructible< _Tp, const optional< _Up > & >, is_constructible< _Tp, optional< _Up > & >, is_constructible< _Tp, const optional< _Up > && >, is_constructible< _Tp, optional< _Up > && >, is_convertible< const optional< _Up > &, _Tp >, is_convertible< optional< _Up > &, _Tp >, is_convertible< const optional< _Up > &&, _Tp >, is_convertible< optional< _Up > &&, _Tp > >

Functions
template<typename _Tp >
constexpr enable_if_t<!_Has_addressof< _Tp >::value, _Tp * >	std::experimental::fundamentals_v1::__constexpr_addressof (_Tp &__t)
void	std::experimental::fundamentals_v1::__throw_bad_optional_access (const char *) __attribute__((__noreturn__))
template<typename _Tp >
constexpr optional< decay_t< _Tp > >	std::experimental::fundamentals_v1::make_optional (_Tp &&__t)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator!= (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator!= (const optional< _Tp > &__lhs, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator!= (nullopt_t, const optional< _Tp > &__rhs) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator!= (const optional< _Tp > &__lhs, _Tp const &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator!= (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator< (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator< (const optional< _Tp > &, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator< (nullopt_t, const optional< _Tp > &__rhs) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator< (const optional< _Tp > &__lhs, const _Tp &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator< (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator<= (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator<= (const optional< _Tp > &__lhs, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator<= (nullopt_t, const optional< _Tp > &) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator<= (const optional< _Tp > &__lhs, const _Tp &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator<= (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator== (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator== (const optional< _Tp > &__lhs, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator== (nullopt_t, const optional< _Tp > &__rhs) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator== (const optional< _Tp > &__lhs, const _Tp &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator== (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator> (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator> (const optional< _Tp > &__lhs, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator> (nullopt_t, const optional< _Tp > &) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator> (const optional< _Tp > &__lhs, const _Tp &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator> (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator>= (const optional< _Tp > &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator>= (const optional< _Tp > &, nullopt_t) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator>= (nullopt_t, const optional< _Tp > &__rhs) noexcept
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator>= (const optional< _Tp > &__lhs, const _Tp &__rhs)
template<typename _Tp >
constexpr bool	std::experimental::fundamentals_v1::operator>= (const _Tp &__lhs, const optional< _Tp > &__rhs)
template<typename _Tp >
void	std::experimental::fundamentals_v1::swap (optional< _Tp > &__lhs, optional< _Tp > &__rhs) noexcept(noexcept(__lhs.swap(__rhs)))

Variables
constexpr in_place_t	std::experimental::fundamentals_v1::in_place
constexpr nullopt_t	std::experimental::fundamentals_v1::nullopt

Detailed Description

Class template for optional values and surrounding facilities, as described in n3793 "A proposal to add a utility class to represent optional objects (Revision 5)".

Function Documentation

__constexpr_addressof()

template<typename _Tp >

constexpr enable_if_t<!_Has_addressof<_Tp>::value, _Tp*> std::experimental::fundamentals_v1::__constexpr_addressof

(

_Tp &

__t

)

An overload that attempts to take the address of an lvalue as a constant expression. Falls back to __addressof in the presence of an overloaded addressof operator (unary operator&), in which case the call will not be a constant expression.

Definition at line 177 of file optional.

Variable Documentation

in_place

constexpr in_place_t std::experimental::fundamentals_v1::in_place

Tag for in-place construction.

Definition at line 90 of file optional.

nullopt

constexpr nullopt_t std::experimental::fundamentals_v1::nullopt

Tag to disengage optional objects.

Definition at line 109 of file optional.