util::Expected< T, E > Class Template Reference

The util::Expected class provides a standard way for low-level functions to return either error values or result values. More...

#include <expected.h>

Public Member Functions
constexpr	Expected ()
constexpr	Expected (ValueType v)
template<class Err >
constexpr	Expected (Unexpected< Err > u)
constexpr bool	has_value () const noexcept
constexpr	operator bool () const noexcept
constexpr const ValueType &	value () const LIFETIMEBOUND
constexpr ValueType &	value () LIFETIMEBOUND
template<class U >
ValueType	value_or (U &&default_value) const &
template<class U >
ValueType	value_or (U &&default_value) &&
constexpr const E &	error () const LIFETIMEBOUND
constexpr E &	error () LIFETIMEBOUND
constexpr ValueType &	operator* () LIFETIMEBOUND
constexpr const ValueType &	operator* () const LIFETIMEBOUND
constexpr ValueType *	operator-> () LIFETIMEBOUND
constexpr const ValueType *	operator-> () const LIFETIMEBOUND

Private Types
using	ValueType = std::conditional_t< std::is_same_v< T, void >, std::monostate, T >

Private Attributes
std::variant< ValueType, E >	m_data

Detailed Description

template<class T, class E>
class util::Expected< T, E >

The util::Expected class provides a standard way for low-level functions to return either error values or result values.

It provides a smaller version of std::expected from C++23. Missing features can be added, if needed.

Definition at line 33 of file expected.h.

Member Typedef Documentation

ValueType

template<class T , class E >

using util::Expected< T, E >::ValueType = std::conditional_t<std::is_same_v<T, void>, std::monostate, T>

private

Definition at line 36 of file expected.h.

Constructor & Destructor Documentation

Expected() [1/3]

template<class T , class E >

constexpr util::Expected< T, E >::Expected ( )

inlineconstexpr

Definition at line 40 of file expected.h.

Expected() [2/3]

template<class T , class E >

constexpr util::Expected< T, E >::Expected ( ValueType  v )

inlineconstexpr

Definition at line 41 of file expected.h.

Expected() [3/3]

template<class T , class E >

template<class Err >

constexpr util::Expected< T, E >::Expected ( Unexpected< Err >  u )

inlineconstexpr

Definition at line 43 of file expected.h.

Member Function Documentation

error() [1/2]

template<class T , class E >

constexpr const E & util::Expected< T, E >::error ( ) const

inlineconstexpr

Definition at line 72 of file expected.h.

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error() [2/2]

template<class T , class E >

constexpr E & util::Expected< T, E >::error ( )

inlineconstexpr

Definition at line 77 of file expected.h.

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has_value()

template<class T , class E >

constexpr bool util::Expected< T, E >::has_value ( ) const

inlineconstexprnoexcept

Definition at line 47 of file expected.h.

operator bool()

template<class T , class E >

constexpr util::Expected< T, E >::operator bool ( ) const

inlineexplicitconstexprnoexcept

Definition at line 48 of file expected.h.

operator*() [1/2]

template<class T , class E >

constexpr const ValueType & util::Expected< T, E >::operator* ( ) const

inlineconstexpr

Definition at line 84 of file expected.h.

operator*() [2/2]

template<class T , class E >

constexpr ValueType & util::Expected< T, E >::operator* ( )

inlineconstexpr

Definition at line 83 of file expected.h.

operator->() [1/2]

template<class T , class E >

constexpr const ValueType * util::Expected< T, E >::operator-> ( ) const

inlineconstexpr

Definition at line 87 of file expected.h.

operator->() [2/2]

template<class T , class E >

constexpr ValueType * util::Expected< T, E >::operator-> ( )

inlineconstexpr

Definition at line 86 of file expected.h.

value() [1/2]

template<class T , class E >

constexpr const ValueType & util::Expected< T, E >::value ( ) const

inlineconstexpr

Definition at line 50 of file expected.h.

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value() [2/2]

template<class T , class E >

constexpr ValueType & util::Expected< T, E >::value ( )

inlineconstexpr

Definition at line 55 of file expected.h.

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value_or() [1/2]

template<class T , class E >

template<class U >

ValueType util::Expected< T, E >::value_or ( U &&  default_value ) &&

inline

Definition at line 67 of file expected.h.

value_or() [2/2]

template<class T , class E >

template<class U >

ValueType util::Expected< T, E >::value_or ( U &&  default_value ) const &

inline

Definition at line 62 of file expected.h.

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Member Data Documentation

m_data

template<class T , class E >

std::variant<ValueType, E> util::Expected< T, E >::m_data

private

Definition at line 37 of file expected.h.

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

• src/util/expected.h