From 888f4f09b0321f1294f185f6cbe8e4dcf1c6686c Mon Sep 17 00:00:00 2001
From: bloeys <bloeys@outlook.com>
Date: Fri, 10 Jun 2022 11:30:53 +0400
Subject: [PATCH] Copy function

---
 nset.go      | 19 +++++++++++++++++++
 nset_test.go |  5 ++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/nset.go b/nset.go
index 7589d97..b23f1f7 100644
--- a/nset.go
+++ b/nset.go
@@ -149,6 +149,25 @@ func (n *NSet[T]) String() string {
 	return b.String()
 }
 
+func (n *NSet[T]) Copy() *NSet[T] {
+
+	newSet := NewNSet[T]()
+	for i := 0; i < len(n.Buckets); i++ {
+
+		b := &n.Buckets[i]
+		newB := &newSet.Buckets[i]
+
+		newB.StorageUnitCount = b.StorageUnitCount
+		newB.Data = make([]StorageType, len(b.Data))
+
+		copy(newB.Data, b.Data)
+	}
+
+	newSet.StorageUnitCount = n.StorageUnitCount
+	return newSet
+
+}
+
 func NewNSet[T IntsIf]() *NSet[T] {
 
 	n := &NSet[T]{
diff --git a/nset_test.go b/nset_test.go
index 5830525..24e96c4 100755
--- a/nset_test.go
+++ b/nset_test.go
@@ -34,8 +34,11 @@ func TestNSet(t *testing.T) {
 	IsEq(t, nset.BucketCount-1, n.GetBucketIndex(math.MaxUint32))
 	IsEq(t, math.MaxUint32/64/nset.BucketCount, n.GetStorageUnitIndex(math.MaxUint32))
 
+	nCopy := n.Copy()
 	n.Remove(1)
-	AllTrue(t, n.Contains(0), n.Contains(63), !n.Contains(1))
+
+	AllTrue(t, n.Contains(0), n.Contains(63), !n.Contains(1), nCopy.ContainsAll(0, 1, 63, math.MaxUint32))
+
 }
 
 func TestNSetFullRange(t *testing.T) {