libcaf  0.16.0
Public Types | Public Member Functions | Static Public Attributes | Related Functions | List of all members
caf::expected< T > Class Template Reference

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
 

Public Member Functions

template<class U >
 expected (U x, typename std::enable_if< std::is_convertible< U, T >::value >::type *=nullptr)
 
 expected (T &&x) noexcept(nothrow_move)
 
 expected (const T &x) noexcept(nothrow_copy)
 
 expected (caf::error e) noexcept
 
 expected (no_error_t) noexcept
 
 expected (const expected &other) noexcept(nothrow_copy)
 
template<class Code , class E = enable_if_has_make_error_t<Code>>
 expected (Code code)
 
 expected (expected &&other) noexcept(nothrow_move)
 
expectedoperator= (const expected &other) noexcept(nothrow_copy)
 
expectedoperator= (expected &&other) noexcept(nothrow_move)
 
expectedoperator= (const T &x) noexcept(nothrow_copy)
 
expectedoperator= (T &&x) noexcept(nothrow_move)
 
template<class U >
std::enable_if< std::is_convertible< U, T >::value, expected & >::type operator= (U x)
 
expectedoperator= (caf::error e) noexcept
 
template<class Code >
enable_if_has_make_error_t< Code, expected & > operator= (Code code)
 
T & value () noexcept
 Returns the contained value. More...
 
T & operator* () noexcept
 Returns the contained value. More...
 
T * operator-> () noexcept
 Returns the contained value. More...
 
caf::errorerror () noexcept
 Returns the contained error. More...
 
const T & cvalue () const noexcept
 Returns the contained value. More...
 
const T & value () const noexcept
 Returns the contained value. More...
 
const T & operator* () const noexcept
 Returns the contained value. More...
 
const T * operator-> () const noexcept
 Returns the contained value. More...
 
 operator bool () const noexcept
 Returns true if the object holds a value (is engaged). More...
 
bool engaged () const noexcept
 Returns true if the object holds a value (is engaged).
 
const caf::errorcerror () const noexcept
 Returns the contained error. More...
 
const caf::errorerror () const noexcept
 Returns the contained error. More...
 

Static Public Attributes

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

Related Functions

(Note that these are not member functions.)

constexpr no_error_t no_error = no_error_t{}
 The only instance of ::no_error_t.
 
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 E >
enable_if_has_make_error_t< E, bool > operator== (const expected< T > &x, E y)
 
template<class T , class E >
enable_if_has_make_error_t< E, bool > operator== (E 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 E >
enable_if_has_make_error_t< E, bool > operator!= (const expected< T > &x, E y)
 
template<class T , class E >
enable_if_has_make_error_t< E, bool > operator!= (E 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<typename 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
TThe type of the result.

Member Function Documentation

◆ cerror()

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

Returns the contained error.

Precondition
engaged() == false.

◆ cvalue()

template<typename T >
const T& caf::expected< T >::cvalue ( ) const
noexcept

Returns the contained value.

Precondition
engaged() == true.

◆ error() [1/2]

template<typename T >
caf::error& caf::expected< T >::error ( )
noexcept

Returns the contained error.

Precondition
engaged() == false.

◆ error() [2/2]

template<typename T >
const caf::error& caf::expected< T >::error ( ) const
noexcept

Returns the contained error.

Precondition
engaged() == false.

◆ operator bool()

template<typename T >
caf::expected< T >::operator bool ( ) const
explicitnoexcept

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

◆ operator*() [1/2]

template<typename T >
T& caf::expected< T >::operator* ( )
noexcept

Returns the contained value.

Precondition
engaged() == true.

◆ operator*() [2/2]

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

Returns the contained value.

Precondition
engaged() == true.

◆ operator->() [1/2]

template<typename T >
T* caf::expected< T >::operator-> ( )
noexcept

Returns the contained value.

Precondition
engaged() == true.

◆ operator->() [2/2]

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

Returns the contained value.

Precondition
engaged() == true.

◆ value() [1/2]

template<typename T >
T& caf::expected< T >::value ( )
noexcept

Returns the contained value.

Precondition
engaged() == true.

◆ value() [2/2]

template<typename T >
const T& caf::expected< T >::value ( ) const
noexcept

Returns the contained value.

Precondition
engaged() == true.

Friends And Related Function Documentation

◆ operator!=() [1/8]

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

◆ operator!=() [2/8]

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

◆ operator!=() [3/8]

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

◆ operator!=() [4/8]

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

◆ operator!=() [5/8]

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

◆ operator!=() [6/8]

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

◆ operator!=() [7/8]

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

◆ operator!=() [8/8]

template<typename T >
bool operator!= ( const expected< void > &  x,
const expected< void > &  y 
)
related

◆ operator==() [1/8]

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

◆ operator==() [2/8]

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

◆ operator==() [3/8]

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

◆ operator==() [4/8]

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

◆ operator==() [5/8]

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

◆ operator==() [6/8]

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

◆ operator==() [7/8]

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

◆ operator==() [8/8]

template<typename T >
bool operator== ( const expected< void > &  x,
const expected< void > &  y 
)
related

Member Data Documentation

◆ nothrow_copy

template<typename T >
constexpr bool caf::expected< T >::nothrow_copy
static
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<typename T >
constexpr bool caf::expected< T >::nothrow_move
static
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: