Use pointer receivers for unsafeset (#143)

* Revert "less pointers and more memory-efficient Clear()"

This reverts commit 3045cfb.

* Revert "less pointers"

This reverts commit 7aad8e9.

* Switch to pointer receivers, fixes UnmarshalJSON

* Expand test coverage for JSON marshaler interface

Author: ryclarke

Diff for: threadsafe.go

@@ -29,7 +29,7 @@ import "sync"
 
 type threadSafeSet[T comparable] struct {
 	sync.RWMutex
-	uss threadUnsafeSet[T]
+	uss *threadUnsafeSet[T]
 }
 
 func newThreadSafeSet[T comparable]() *threadSafeSet[T] {
@@ -123,7 +123,7 @@ func (t *threadSafeSet[T]) Union(other Set[T]) Set[T] {
 	t.RLock()
 	o.RLock()
 
-	unsafeUnion := t.uss.Union(o.uss).(threadUnsafeSet[T])
+	unsafeUnion := t.uss.Union(o.uss).(*threadUnsafeSet[T])
 	ret := &threadSafeSet[T]{uss: unsafeUnion}
 	t.RUnlock()
 	o.RUnlock()
@@ -136,7 +136,7 @@ func (t *threadSafeSet[T]) Intersect(other Set[T]) Set[T] {
 	t.RLock()
 	o.RLock()
 
-	unsafeIntersection := t.uss.Intersect(o.uss).(threadUnsafeSet[T])
+	unsafeIntersection := t.uss.Intersect(o.uss).(*threadUnsafeSet[T])
 	ret := &threadSafeSet[T]{uss: unsafeIntersection}
 	t.RUnlock()
 	o.RUnlock()
@@ -149,7 +149,7 @@ func (t *threadSafeSet[T]) Difference(other Set[T]) Set[T] {
 	t.RLock()
 	o.RLock()
 
-	unsafeDifference := t.uss.Difference(o.uss).(threadUnsafeSet[T])
+	unsafeDifference := t.uss.Difference(o.uss).(*threadUnsafeSet[T])
 	ret := &threadSafeSet[T]{uss: unsafeDifference}
 	t.RUnlock()
 	o.RUnlock()
@@ -162,7 +162,7 @@ func (t *threadSafeSet[T]) SymmetricDifference(other Set[T]) Set[T] {
 	t.RLock()
 	o.RLock()
 
-	unsafeDifference := t.uss.SymmetricDifference(o.uss).(threadUnsafeSet[T])
+	unsafeDifference := t.uss.SymmetricDifference(o.uss).(*threadUnsafeSet[T])
 	ret := &threadSafeSet[T]{uss: unsafeDifference}
 	t.RUnlock()
 	o.RUnlock()
@@ -177,7 +177,7 @@ func (t *threadSafeSet[T]) Clear() {
 
 func (t *threadSafeSet[T]) Remove(v T) {
 	t.Lock()
-	delete(t.uss, v)
+	delete(*t.uss, v)
 	t.Unlock()
 }
 
@@ -190,12 +190,12 @@ func (t *threadSafeSet[T]) RemoveAll(i ...T) {
 func (t *threadSafeSet[T]) Cardinality() int {
 	t.RLock()
 	defer t.RUnlock()
-	return len(t.uss)
+	return len(*t.uss)
 }
 
 func (t *threadSafeSet[T]) Each(cb func(T) bool) {
 	t.RLock()
-	for elem := range t.uss {
+	for elem := range *t.uss {
 		if cb(elem) {
 			break
 		}
@@ -208,7 +208,7 @@ func (t *threadSafeSet[T]) Iter() <-chan T {
 	go func() {
 		t.RLock()
 
-		for elem := range t.uss {
+		for elem := range *t.uss {
 			ch <- elem
 		}
 		close(ch)
@@ -224,7 +224,7 @@ func (t *threadSafeSet[T]) Iterator() *Iterator[T] {
 	go func() {
 		t.RLock()
 	L:
-		for elem := range t.uss {
+		for elem := range *t.uss {
 			select {
 			case <-stopCh:
 				break L
@@ -253,7 +253,7 @@ func (t *threadSafeSet[T]) Equal(other Set[T]) bool {
 func (t *threadSafeSet[T]) Clone() Set[T] {
 	t.RLock()
 
-	unsafeClone := t.uss.Clone().(threadUnsafeSet[T])
+	unsafeClone := t.uss.Clone().(*threadUnsafeSet[T])
 	ret := &threadSafeSet[T]{uss: unsafeClone}
 	t.RUnlock()
 	return ret
@@ -275,7 +275,7 @@ func (t *threadSafeSet[T]) Pop() (T, bool) {
 func (t *threadSafeSet[T]) ToSlice() []T {
 	keys := make([]T, 0, t.Cardinality())
 	t.RLock()
-	for elem := range t.uss {
+	for elem := range *t.uss {
 		keys = append(keys, elem)
 	}
 	t.RUnlock()

Diff for: threadsafe_test.go

@@ -584,17 +584,7 @@ func Test_UnmarshalJSON(t *testing.T) {
 		t.Errorf("Expected no difference, got: %v", expected.Difference(actual))
 	}
 }
-func TestThreadUnsafeSet_UnmarshalJSON(t *testing.T) {
-	expected := NewThreadUnsafeSet[int64](1, 2, 3)
-	actual := NewThreadUnsafeSet[int64]()
-	err := actual.UnmarshalJSON([]byte(`[1, 2, 3]`))
-	if err != nil {
-		t.Errorf("Error should be nil: %v", err)
-	}
-	if !expected.Equal(actual) {
-		t.Errorf("Expected no difference, got: %v", expected.Difference(actual))
-	}
-}
+
 func Test_MarshalJSON(t *testing.T) {
 	expected := NewSet(
 		[]string{