Suppose I have an ICollection<SomeClass>
.
I have the following two variables:
SomeClass old;
SomeClass new;
How can I achieve something like the following using an ICollection<SomeClass>
?
// old is guaranteed to be inside collection
collection.Replace(old, new);
There is no black magic here: ICollection<T>
is not ordered and only provides Add
/Remove
methods. Your only solution would be to check if the actual implementation is something more, such as IList<T>
:
public static void Swap<T>(this ICollection<T> collection, T oldValue, T newValue)
{
// In case the collection is ordered, we'll be able to preserve the order
var collectionAsList = collection as IList<T>;
if (collectionAsList != null)
{
var oldIndex = collectionAsList.IndexOf(oldValue);
collectionAsList.RemoveAt(oldIndex);
collectionAsList.Insert(oldIndex, newValue);
}
else
{
// No luck, so just remove then add
collection.Remove(oldValue);
collection.Add(newValue);
}
}
The ICollection<T>
interface is quite limited, you will have to use Remove()
and Add()
collection.Remove(old);
collection.Add(new);
Do that:
yourCollection.ToList()[index] = newValue;