Function pointer for a completion callback.

When we call this, we will send the completed future, along with the user data that you specified when you set up the callback.

Construct an untyped future.

Copy constructor and operator.

Increment the reference count when creating a copy of the future.

Register a single callback that will be called at most once, when the future is completed.

If you call anyOnCompletion() method more than once on the same future, only the most recent callback you registered withOnCompletion() will be called. When your callback is called, the user_data that you supplied here will be passed back as the second parameter.

Register a single callback that will be called at most once, when the future is completed.

If you call anyOnCompletion() method more than once on the same future, only the most recent callback you registered withOnCompletion() will be called.Note: This method is not available when using STLPort on Android, asstd::function is not supported on STLPort.

Future will become invalid.

Whenstatus() isfirebase::kFutureStatusComplete, returns the API-defined error code.

Otherwise, return value is undefined.

Whenstatus() isfirebase::kFutureStatusComplete, returns the API-defined error message, as human-readable text, or an empty string if the API does not provide a human readable description of the error.

Note: The returned pointer is only valid for the lifetime of theFuture or its copies.

Returns true if the two Futures reference different results.

Copy an untyped future.

Returns true if the two Futures reference the same result.

Result of the asynchronous call, or nullptr if the result is still pending.

Cast is required since GetFutureResult() returns void*.

Completion status of the asynchronous call.