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

Holds either a success value or an error value. More...

#include <expected.h>

Public Member Functions
	Expected (const Expected &other)=default
	Copies the contained alternative. More...
	Expected (Expected &&other)=default
	Moves the contained alternative. More...
template<typename U >
requires std::is_convertible_v< U, T > std::is_convertible_v< U, E >	Expected (U &&value)
	Constructs the variant alternative selected by std::variant<T, E>. More...
template<typename U >
requires std::is_convertible_v< U, E >	Expected (Unexpected< U > &&unex)
	Constructs an error result from an unexpected value. More...
constexpr bool	has_value () const noexcept
constexpr	operator bool () const noexcept
const T &	value () const
const E &	error () const
constexpr const T *	operator-> () const noexcept

Detailed Description

template<typename T, typename E>
class quicr::Expected< T, E >

Holds either a success value or an error value.

Template Parameters

T	Success type.
E	Error type.

Note

This class is not internally synchronized. References and pointers returned by accessors are invalidated when the Expected object is destroyed or moved.

Examples

simple_publish/main.cpp, and simple_subscribe/main.cpp.

Constructor & Destructor Documentation

Expected() [1/4]

template<typename T , typename E >

quicr::Expected< T, E >::Expected ( const Expected< T, E > &  other )

default

Copies the contained alternative.

Parameters

other

Result to copy.

Expected() [2/4]

template<typename T , typename E >

quicr::Expected< T, E >::Expected ( Expected< T, E > &&  other )

default

Moves the contained alternative.

Parameters

other

Result to move.

Expected() [3/4]

template<typename T , typename E >

template<typename U >

requires std::is_convertible_v<U, T> std::is_convertible_v<U, E> quicr::Expected< T, E >::Expected ( U &&  value )

inline

Constructs the variant alternative selected by std::variant<T, E>.

Template Parameters

U	Type convertible to T or E.

Parameters

value

Value forwarded to the variant.

Exceptions

Any	exception thrown while constructing the selected alternative.

Expected() [4/4]

template<typename T , typename E >

template<typename U >

requires std::is_convertible_v<U, E> quicr::Expected< T, E >::Expected ( Unexpected< U > &&  unex )

inline

Constructs an error result from an unexpected value.

Template Parameters

U	Error source type convertible to E.

Parameters

unex	Wrapper whose error is copied into this result.

Member Function Documentation

error()

template<typename T , typename E >

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

inline

Returns

A reference to the error value.

Exceptions

std::bad_variant_access

If this object contains a success value.

has_value()

template<typename T , typename E >

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

inlineconstexprnoexcept

Returns

true when the success alternative is active.

operator bool()

template<typename T , typename E >

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

inlineexplicitconstexprnoexcept

Returns

The same state reported by has_value().

operator->()

template<typename T , typename E >

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

inlineconstexprnoexcept

Returns

A pointer to the success value.

Warning

Calling this while the object contains an error terminates the process because the function is noexcept and its internal value access throws.

value()

template<typename T , typename E >

const T& quicr::Expected< T, E >::value ( ) const

inline

Returns

A reference to the success value.

Exceptions

std::bad_variant_access

If this object contains an error.

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

• include/quicr/utilities/expected.h