Future<T>.value constructor Null safety
- [FutureOr<
T> ? value]
Creates a future completed with value.
If value is a future, the created future waits for the
value future to complete, and then completes with the same result.
Since a value future can complete with an error, so can the future
created by Future.value, even if the name suggests otherwise.
If value is not a Future, the created future is completed
with the value value,
equivalently to new Future<T>.sync(() => value).
If value is omitted or null, it is converted to FutureOr<T> by
value as FutureOr<T>. If T is not nullable, then the value is
required, otherwise the construction throws.
Use Completer to create a future and complete it later.
Implementation
@pragma("vm:entry-point")
@pragma("vm:prefer-inline")
factory Future.value([FutureOr<T>? value]) {
return new _Future<T>.immediate(value == null ? value as T : value);
}