removeObjectsAtIndexes for Swift arrays

Question

What is a Swift array equivalent to NSMutableArray\'s -removeObjectsAtIndexes:? Removing each index one by one doesn\'t work, as remaining indexes

Answer 1

I have not tested this, but I would bet that a non-mutating version is faster if it copies contiguous subranges. Something like:

extension Array {
        public func removing(indices indicesToRemove: IndexSet) -> Self {
            guard let lastIndex = indicesToRemove.last else {
                return self
            }

            assert(lastIndex <= (self.count - 1), message: "Index set contains out of bounds indices")

            var result = Self()
            result.reserveCapacity(self.count - indicesToRemove.count)

            let indicesToKeep = IndexSet(self.indices).subtracting(indicesToRemove)
            let rangesToKeep = indicesToKeep.rangeView

            rangesToKeep.forEach { (range) in
                result.append(contentsOf: self[range])
            }

            return result
        }
}