Offsets the given index by the specified distance, or so that it equals the given limiting index.
SDK
- Xcode 9.3+
Framework
- Swift Standard Library
Declaration
func formIndex(_ i: inout Dictionary<Key, Value>.Index, offsetBy distance: Int, limitedBy limit: Dictionary<Key, Value>.Index) -> Bool
Parameters
iA valid index of the collection.
distanceThe distance to offset
i.distancemust not be negative unless the collection conforms to theBidirectionalprotocol.Collection limitA valid index of the collection to use as a limit. If
distance > 0, a limit that is less thanihas no effect. Likewise, ifdistance < 0, a limit that is greater thanihas no effect.
Return Value
true if i has been offset by exactly distance steps without going beyond limit; otherwise, false. When the return value is false, the value of i is equal to limit.
Discussion
The value passed as distance must not offset i beyond the bounds of the collection, unless the index passed as limit prevents offsetting beyond those bounds.
Complexity: O(1) if the collection conforms to Random; otherwise, O(k), where k is the absolute value of distance.