pub fn gather<C, T>(
world: &C,
root: i32,
value: T,
) -> Result<Option<Vec<T>>, PlacementError>where
C: Communicator,
T: Serialize + DeserializeOwned,Expand description
Collects one value from every rank in rank order on the root.
Every rank supplies one owned value. Only the root receives Some(values);
all other ranks receive None.