Description

template<class T, class E>
class Sawyer::Result< T, E >

Result containing a value or an error.

Definition at line 270 of file Result.h.

#include <util/Sawyer/Result.h>

Public Types
using	OkValue = T

using	ErrorValue = E

using	OkType = Ok< T >

using	ErrorType = Error< E >

Public Member Functions
template<class U = T>
	Result (const Ok< U > &ok)

template<class F = E>
	Result (const Error< F > &error)

template<class U = T>
Result &	operator= (const Ok< U > &ok)
	Assign an Ok value to this result. More...

template<class F = E>
Result &	operator= (const Error< F > &error)
	Assign an Error value to this result. More...

template<class U = T>
bool	operator== (const Ok< U > &ok) const
	Test whether this result has the specified Ok value. More...

template<class U = T>
bool	operator!= (const Ok< U > &ok) const
	Test whether this result does not have the specified Ok value. More...

template<class F = E>
bool	operator== (const Error< F > &error) const
	Test whether this result has the specified Error value. More...

template<class F = E>
bool	operator!= (const Error< F > &error) const
	Test whether this result does not have the specified Error value. More...

template<class U , class F >
bool	operator== (const Result< U, F > &other) const
	Test whether this result is equal to the other result. More...

template<class U , class F >
bool	operator!= (const Result< U, F > &other) const
	Test whether this result is unequal to the other result. More...

bool	isError () const
	Returns true if the result is an error. More...

const Sawyer::Optional< T >	ok () const
	Convert to Optional<T>. More...

const Sawyer::Optional< E >	error () const
	Convert to Optional<E>. More...

const T &	expect (const std::string &mesg) const
	Returns the success value or throws an exception. More...

const T	orElse (const T &dflt) const
	Returns the contained Ok value or a provided default. More...

template<class Fn >
std::enable_if< is_invocable< Fn, ErrorValue >::value, const Result >::type	orElse (Fn fn) const
	Returns the contained Ok value, or calls a function. More...

template<class F >
const Result< T, F >	orElse (const Result< T, F > &other) const
	Returns this value or the other result. More...

const T &	orDefault () const
	Returns the okay value or a default constructed value. More...

template<class Exception = E>
const T &	orThrow () const
	Returns the value or throws an exception. More...

template<class Exception = E>
const T &	orThrow (const Exception &e) const
	Returns the value or throws an exception constructed from the specified value. More...

template<class Fn >
std::enable_if< is_invocable< Fn, OkValue >::value, const Result >::type	andThen (Fn fn) const
	Returns the contained Error value, or calls a function. More...

template<class U >
const Result< U, E >	andThen (const Result< U, E > &other) const
	Returns this error or the other result. More...

const E &	expectError (const std::string &mesg) const
	Returns the error value or throws an exception. More...

const E &	unwrapError () const
	Returns the error value or throws an exception. More...

template<class U >
bool	contains (const U &value) const
	Returns true if this result contains the specified okay value. More...

template<class F >
bool	containsError (const F &error) const
	Returns true if this result contains the specified error value. More...

template<class U >
bool	assignTo (U &out) const
	Conditionally save a value. More...


bool	isOk () const
	Returns true if the result is okay.

	operator bool () const
	Returns true if the result is okay.


const T &	unwrap () const
	Returns the success value or throws an exception. More...

const T &	operator* () const
	Returns the success value or throws an exception. More...

Member Function Documentation

template<class T, class E>

template<class U = T>

Result& Sawyer::Result< T, E >::operator= ( const Ok< U > & ok )

inline

Assign an Ok value to this result.

Definition at line 321 of file Result.h.

template<class T, class E>

template<class F = E>

Result& Sawyer::Result< T, E >::operator= ( const Error< F > & error )

inline

Assign an Error value to this result.

Definition at line 328 of file Result.h.

template<class T, class E>

template<class U = T>

bool Sawyer::Result< T, E >::operator== ( const Ok< U > & ok ) const

inline

Test whether this result has the specified Ok value.

Definition at line 335 of file Result.h.

References Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::ok().

template<class T, class E>

template<class U = T>

bool Sawyer::Result< T, E >::operator!= ( const Ok< U > & ok ) const

inline

Test whether this result does not have the specified Ok value.

Definition at line 341 of file Result.h.

References Sawyer::Result< T, E >::ok().

template<class T, class E>

template<class F = E>

bool Sawyer::Result< T, E >::operator== ( const Error< F > & error ) const

inline

Test whether this result has the specified Error value.

Definition at line 347 of file Result.h.

References Sawyer::Result< T, E >::error(), and Sawyer::Result< T, E >::isError().

template<class T, class E>

template<class F = E>

bool Sawyer::Result< T, E >::operator!= ( const Error< F > & error ) const

inline

Test whether this result does not have the specified Error value.

Definition at line 353 of file Result.h.

References Sawyer::Result< T, E >::error().

template<class T, class E>

template<class U , class F >

bool Sawyer::Result< T, E >::operator== ( const Result< U, F > & other ) const

inline

Test whether this result is equal to the other result.

Definition at line 359 of file Result.h.

References Sawyer::Result< T, E >::error(), Sawyer::Result< T, E >::isError(), Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::ok().

template<class T, class E>

template<class U , class F >

bool Sawyer::Result< T, E >::operator!= ( const Result< U, F > & other ) const

inline

Test whether this result is unequal to the other result.

Definition at line 366 of file Result.h.

template<class T, class E>

bool Sawyer::Result< T, E >::isError ( ) const

inline

Returns true if the result is an error.

Definition at line 382 of file Result.h.

References Sawyer::Result< T, E >::isOk().

Referenced by Sawyer::Result< T, E >::operator==().

template<class T, class E>

const Sawyer::Optional<T> Sawyer::Result< T, E >::ok ( ) const

inline

Convert to Optional<T>.

If this result is okay, then return the result, otherwise return nothing.

Definition at line 389 of file Result.h.

References Sawyer::Result< T, E >::isOk().

Referenced by Sawyer::Result< T, E >::andThen(), Sawyer::Result< T, E >::operator!=(), and Sawyer::Result< T, E >::operator==().

template<class T, class E>

const Sawyer::Optional<E> Sawyer::Result< T, E >::error ( ) const

inline

Convert to Optional<E>.

If this result is an error, then return the error, otherwise return nothing.

Definition at line 400 of file Result.h.

References Sawyer::Result< T, E >::isOk().

Referenced by Sawyer::Result< T, E >::containsError(), Sawyer::Result< T, E >::operator!=(), Sawyer::Result< T, E >::operator==(), Sawyer::Result< T, E >::orElse(), and Sawyer::Result< T, E >::orThrow().

template<class T, class E>

const T& Sawyer::Result< T, E >::expect ( const std::string & mesg ) const

inline

Returns the success value or throws an exception.

If this result is okay, then returns its value, otherwise throws an std::runtime_error with the specified string.

Definition at line 411 of file Result.h.

References Sawyer::Result< T, E >::isOk().

Referenced by Sawyer::Result< T, E >::unwrap().

template<class T, class E>

const T& Sawyer::Result< T, E >::unwrap ( ) const

inline

Returns the success value or throws an exception.

If this result is okay, then returns its value, otherwise throws an std::runtime_error.

Definition at line 424 of file Result.h.

References Sawyer::Result< T, E >::expect().

Referenced by Sawyer::Result< T, E >::assignTo(), Sawyer::Result< T, E >::contains(), Sawyer::Result< T, E >::operator*(), Sawyer::Result< T, E >::orDefault(), Sawyer::Result< T, E >::orElse(), and Sawyer::Result< T, E >::orThrow().

template<class T, class E>

const T& Sawyer::Result< T, E >::operator* ( ) const

inline

Returns the success value or throws an exception.

If this result is okay, then returns its value, otherwise throws an std::runtime_error.

Definition at line 427 of file Result.h.

References Sawyer::Result< T, E >::unwrap().

template<class T, class E>

const T Sawyer::Result< T, E >::orElse ( const T & dflt ) const

inline

Returns the contained Ok value or a provided default.

Definition at line 433 of file Result.h.

References Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::unwrap().

template<class T, class E>

template<class Fn >

std::enable_if<is_invocable<Fn, ErrorValue>::value, const Result>::type Sawyer::Result< T, E >::orElse ( Fn fn ) const

inline

Returns the contained Ok value, or calls a function.

If this result is okay, then returns this result, otherwise calls the specified function, fn, with this result's Error value and returns the function's result.

Definition at line 443 of file Result.h.

References Sawyer::Result< T, E >::error(), and Sawyer::Result< T, E >::isOk().

template<class T, class E>

template<class F >

const Result<T, F> Sawyer::Result< T, E >::orElse ( const Result< T, F > & other ) const

inline

Returns this value or the other result.

If this result is okay then return it, otherwise returns the other result.

Definition at line 455 of file Result.h.

References Sawyer::Result< T, E >::isOk().

template<class T, class E>

const T& Sawyer::Result< T, E >::orDefault ( ) const

inline

Returns the okay value or a default constructed value.

Definition at line 464 of file Result.h.

References Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::unwrap().

template<class T, class E>

template<class Exception = E>

const T& Sawyer::Result< T, E >::orThrow ( ) const

inline

Returns the value or throws an exception.

If the result is okay, then its value is returned, otherwise either the error is thrown or it is used to construct the specified Exception which is then thrown.

Definition at line 474 of file Result.h.

References Sawyer::Result< T, E >::error(), Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::unwrap().

template<class T, class E>

template<class Exception = E>

const T& Sawyer::Result< T, E >::orThrow ( const Exception & e ) const

inline

Returns the value or throws an exception constructed from the specified value.

Definition at line 484 of file Result.h.

References Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::unwrap().

template<class T, class E>

template<class Fn >

std::enable_if<is_invocable<Fn, OkValue>::value, const Result>::type Sawyer::Result< T, E >::andThen ( Fn fn ) const

inline

Returns the contained Error value, or calls a function.

If this result is an error, then it's returned. Otherwise the okay value is passed to the specified function and that function's return value is returned.

Definition at line 498 of file Result.h.

References Sawyer::Result< T, E >::isOk(), and Sawyer::Result< T, E >::ok().

template<class T, class E>

template<class U >

const Result<U, E> Sawyer::Result< T, E >::andThen ( const Result< U, E > & other ) const