Represents the result of a computation which can either complete successfully with an instance of type T or fail with an error. More...

#include <expected.hpp>

Public Types
using	value_type = T

using	error_type = caf::error

template<class U >
using	rebind = expected< U >

Public Member Functions
template<class U , class = std::enable_if_t<std::is_convertible_v<U, T> \|\| is_error_code_enum_v<U>>>
	expected (U x)

	expected (T &&x) noexcept(nothrow_move)

	expected (const T &x) noexcept(nothrow_copy)

	expected (caf::error e) noexcept

	expected (const expected &other) noexcept(nothrow_copy)

	expected (expected &&other) noexcept(nothrow_move)

template<class... Ts>
	expected (std::in_place_t, Ts &&... xs)

expected &	operator= (const expected &other) noexcept(nothrow_copy)

expected &	operator= (expected &&other) noexcept(nothrow_move)

expected &	operator= (const T &x) noexcept(nothrow_copy)

expected &	operator= (T &&x) noexcept(nothrow_move)

template<class U >
std::enable_if< std::is_convertible< U, T >::value, expected & >::type	operator= (U x)

expected &	operator= (caf::error e) noexcept

template<class Enum , class = std::enable_if_t<is_error_code_enum_v<Enum>>>
expected &	operator= (Enum code)

	operator bool () const noexcept
	Returns `true` if the object holds a value (is engaged).

bool	has_value () const noexcept
	Returns `true` if the object holds a value (is engaged).

bool	engaged () const noexcept
	Returns `true` if the object holds a value (is engaged).

template<class... Args>
std::enable_if_t< std::is_nothrow_constructible_v< T, Args... >, T & >	emplace (Args &&... args) noexcept

void	swap (expected &other) noexcept(nothrow_move &&nothrow_swap)

const T &	cvalue () const noexcept
	Returns the contained value.

T &	value () &
	Returns the contained value.

const T &	value () const &
	Returns the contained value.

T &&	value () &&
	Returns the contained value.

const T &&	value () const &&
	Returns the contained value.

template<class U >
T	value_or (U &&fallback) const &
	Returns the contained value if there is one, otherwise returns `fallback`.

template<class U >
T	value_or (U &&fallback) &&
	Returns the contained value if there is one, otherwise returns `fallback`.

T &	operator* () &noexcept
	Returns the contained value.

const T &	operator* () const &noexcept
	Returns the contained value.

T &&	operator* () &&noexcept
	Returns the contained value.

const T &&	operator* () const &&noexcept
	Returns the contained value.

T *	operator-> () noexcept
	Returns the contained value.

const T *	operator-> () const noexcept
	Returns the contained value.

const caf::error &	cerror () const noexcept
	Returns the contained error.

caf::error &	error () &noexcept
	Returns the contained error.

const caf::error &	error () const &noexcept
	Returns the contained error.

caf::error &&	error () &&noexcept
	Returns the contained error.

const caf::error &&	error () const &&noexcept
	Returns the contained error.

template<class F >
auto	and_then (F &&f) &

template<class F >
auto	and_then (F &&f) &&

template<class F >
auto	and_then (F &&f) const &

template<class F >
auto	and_then (F &&f) const &&

template<class F >
expected	or_else (F &&f) &

template<class F >
expected	or_else (F &&f) &&

template<class F >
expected	or_else (F &&f) const &

template<class F >
expected	or_else (F &&f) const &&

template<class F >
auto	transform (F &&f) &

template<class F >
auto	transform (F &&f) &&

template<class F >
auto	transform (F &&f) const &

template<class F >
auto	transform (F &&f) const &&

template<class F >
expected	transform_or (F &&f) &

template<class F >
expected	transform_or (F &&f) &&

template<class F >
expected	transform_or (F &&f) const &

template<class F >
expected	transform_or (F &&f) const &&

Static Public Attributes
static constexpr bool	nothrow_move
	Stores whether move construct and move assign never throw.

static constexpr bool	nothrow_copy
	Stores whether copy construct and copy assign never throw.

static constexpr bool	nothrow_swap = std::is_nothrow_swappable_v<T>
	Stores whether swap() never throws.

Related Functions
(Note that these are not member functions.)
template<class T >
auto	operator== (const expected< T > &x, const expected< T > &y) -> decltype(x==y)

template<class T , class U >
auto	operator== (const expected< T > &x, const U &y) -> decltype(*x==y)

template<class T , class U >
auto	operator== (const T &x, const expected< U > &y) -> decltype(x==*y)

template<class T >
bool	operator== (const expected< T > &x, const error &y)

template<class T >
bool	operator== (const error &x, const expected< T > &y)

template<class T , class Enum >
std::enable_if_t< is_error_code_enum_v< Enum >, bool >	operator== (const expected< T > &x, Enum y)

template<class T , class Enum >
std::enable_if_t< is_error_code_enum_v< Enum >, bool >	operator== (Enum x, const expected< T > &y)

template<class T >
auto	operator!= (const expected< T > &x, const expected< T > &y) -> decltype(x==y)

template<class T , class U >
auto	operator!= (const expected< T > &x, const U &y) -> decltype(*x==y)

template<class T , class U >
auto	operator!= (const T &x, const expected< U > &y) -> decltype(x==*y)

template<class T >
bool	operator!= (const expected< T > &x, const error &y)

template<class T >
bool	operator!= (const error &x, const expected< T > &y)

template<class T , class Enum >
std::enable_if_t< is_error_code_enum_v< Enum >, bool >	operator!= (const expected< T > &x, Enum y)

template<class T , class Enum >
std::enable_if_t< is_error_code_enum_v< Enum >, bool >	operator!= (Enum x, const expected< T > &y)

bool	operator== (const expected< void > &x, const expected< void > &y)

bool	operator!= (const expected< void > &x, const expected< void > &y)

Detailed Description

template<class T>
class caf::expected< T >

Represents the result of a computation which can either complete successfully with an instance of type T or fail with an error.

Template Parameters

T	The type of the result.

Member Function Documentation

◆ cerror()

template<class T >

const caf::error & caf::expected< T >::cerror ( ) const

noexcept

Returns the contained error.

Precondition: has_value() == false.

◆ cvalue()

template<class T >

const T & caf::expected< T >::cvalue ( ) const

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ error() [1/4]

template<class T >

caf::error && caf::expected< T >::error ( ) &&

noexcept

Returns the contained error.

Precondition: has_value() == false.

◆ error() [2/4]

template<class T >

caf::error & caf::expected< T >::error ( ) &

noexcept

Returns the contained error.

Precondition: has_value() == false.

◆ error() [3/4]

template<class T >

const caf::error && caf::expected< T >::error ( ) const &&

noexcept

Returns the contained error.

Precondition: has_value() == false.

◆ error() [4/4]

template<class T >

const caf::error & caf::expected< T >::error ( ) const &

noexcept

Returns the contained error.

Precondition: has_value() == false.

◆ operator bool()

template<class T >

caf::expected< T >::operator bool ( ) const

explicitnoexcept

Returns true if the object holds a value (is engaged).

◆ operator*() [1/4]

template<class T >

T && caf::expected< T >::operator* ( ) &&

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ operator*() [2/4]

template<class T >

T & caf::expected< T >::operator* ( ) &

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ operator*() [3/4]

template<class T >

const T && caf::expected< T >::operator* ( ) const &&

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ operator*() [4/4]

template<class T >

const T & caf::expected< T >::operator* ( ) const &

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ operator->() [1/2]

template<class T >

const T * caf::expected< T >::operator-> ( ) const

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ operator->() [2/2]

template<class T >

T * caf::expected< T >::operator-> ( )

noexcept

Returns the contained value.

Precondition: has_value() == true.

◆ value() [1/4]

template<class T >

T & caf::expected< T >::value ( ) &

Returns the contained value.

Precondition: has_value() == true.

◆ value() [2/4]

template<class T >

T && caf::expected< T >::value ( ) &&

Returns the contained value.

Precondition: has_value() == true.

◆ value() [3/4]

template<class T >

const T & caf::expected< T >::value ( ) const &

Returns the contained value.

Precondition: has_value() == true.

◆ value() [4/4]

template<class T >

const T && caf::expected< T >::value ( ) const &&

Returns the contained value.

Precondition: has_value() == true.

Member Data Documentation

◆ nothrow_copy

template<class T >

constexpr bool caf::expected< T >::nothrow_copy

staticconstexpr

Initial value:

= std::is_nothrow_copy_constructible<T>::value

&& std::is_nothrow_copy_assignable<T>::value

Stores whether copy construct and copy assign never throw.

◆ nothrow_move

template<class T >

constexpr bool caf::expected< T >::nothrow_move

staticconstexpr

Initial value:

= std::is_nothrow_move_constructible<T>::value

&& std::is_nothrow_move_assignable<T>::value

Stores whether move construct and move assign never throw.

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

libcaf_core/caf/expected.hpp

Public Types

Public Member Functions

Static Public Attributes

Related Functions

Detailed Description

Member Function Documentation

◆ cerror()

◆ cvalue()

◆ error() [1/4]

◆ error() [2/4]

◆ error() [3/4]

◆ error() [4/4]

◆ operator bool()

◆ operator*() [1/4]

◆ operator*() [2/4]

◆ operator*() [3/4]

◆ operator*() [4/4]

◆ operator->() [1/2]

◆ operator->() [2/2]

◆ value() [1/4]

◆ value() [2/4]

◆ value() [3/4]

◆ value() [4/4]

Member Data Documentation

◆ nothrow_copy

◆ nothrow_move