oboe::ResultWithValue< T > Class Template Reference

#include <ResultWithValue.h>

Public Member Functions
	ResultWithValue (oboe::Result error)
	ResultWithValue (T value)
oboe::Result	error () const
T	value () const
	operator bool () const
bool	operator ! () const
	operator Result () const

Static Public Member Functions
static ResultWithValue< T >	createBasedOnSign (T numericResult)

Detailed Description

template<typename T>
class oboe::ResultWithValue< T >

A ResultWithValue can store both the result of an operation (either OK or an error) and a value.

It has been designed for cases where the caller needs to know whether an operation succeeded and, if it did, a value which was obtained during the operation.

For example, when reading from a stream the caller needs to know the result of the read operation and, if it was successful, how many frames were read. Note that ResultWithValue can be evaluated as a boolean so it's simple to check whether the result is OK.

ResultWithValue<int32_t> resultOfRead = myStream.read(&buffer, numFrames, timeoutNanoseconds);

if (resultOfRead) { LOGD("Frames read: %d", resultOfRead.value()); } else { LOGD("Error reading from stream: %s", resultOfRead.error()); }

Constructor & Destructor Documentation

ResultWithValue() [1/2]

template<typename T>

oboe::ResultWithValue< T >::ResultWithValue ( oboe::Result  error )

inline

Construct a ResultWithValue containing an error result.

Parameters

error

The error

ResultWithValue() [2/2]

template<typename T>

oboe::ResultWithValue< T >::ResultWithValue ( T  value )

inlineexplicit

Construct a ResultWithValue containing an OK result and a value.

Parameters

value

the value to store

Member Function Documentation

createBasedOnSign()

template<typename T>

static ResultWithValue<T> oboe::ResultWithValue< T >::createBasedOnSign ( T  numericResult )

inlinestatic

Create a ResultWithValue from a number. If the number is positive the ResultWithValue will have a result of Result::OK and the value will contain the number. If the number is negative the result will be obtained from the negative number (numeric error codes can be found in AAudio.h) and the value will be null.

error()

template<typename T>

oboe::Result oboe::ResultWithValue< T >::error ( ) const

inline

Get the result.

Returns

the result

operator !()

template<typename T>

bool oboe::ResultWithValue< T >::operator ! ( ) const

inline

Quick way to check for an error.

The caller could write something like this: if (!result) { printf("Got error %s\n", convertToText(result.error())); }

Returns

true if an error occurred

operator bool()

template<typename T>

oboe::ResultWithValue< T >::operator bool ( ) const

inlineexplicit

Returns

true if OK

operator Result()

template<typename T>

oboe::ResultWithValue< T >::operator Result ( ) const

inline

Implicitly convert to a Result. This enables easy comparison with Result values. Example:

ResultWithValue result = openStream(); if (result == Result::ErrorNoMemory){ // tell user they're out of memory }

value()

template<typename T>

T oboe::ResultWithValue< T >::value ( ) const

inline

Get the value

Returns

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

• include/oboe/ResultWithValue.h