Class AsyncToken (2.15.1)

Serialize streams of asynchronous operations.

Some asynchronous APIs produce streams of results, where (1) each of these results is obtained asynchronously, and (2) on a single stream, only one of these results can be requested at a time.

Where both conditions apply the APIs will consume an AsyncToken as a parameter, and return a future<std::pair<ResultT,StatusOr<AsyncToken>>. When this future is satisfied, and the StatusOr<> contains an value, the caller can invoke the API once again. Before the future is satisfied the application does not have (and cannot create) a valid AsyncToken to invoke the API again.

Constructors

AsyncToken()

Create an invalid async token.

AsyncToken(AsyncToken &&)

Move constructor. Invalidates rhs.

Parameter
Name Description
rhs AsyncToken &&

AsyncToken(AsyncToken const &)

Disable copying, this is a move-only class.

Parameter
Name Description
AsyncToken const &

Operators

operator=(AsyncToken &&)

Move assignment. Invalidates rhs.

Parameter
Name Description
rhs AsyncToken &&
Returns
Type Description
AsyncToken &

operator=(AsyncToken const &)

Disable copying, this is a move-only class.

Parameter
Name Description
AsyncToken const &
Returns
Type Description
AsyncToken &

Functions

valid() const

Returns false for invalidated instances.

Returns
Type Description
bool