diff --git a/pkg/typex/generic.go b/pkg/typex/generic.go
new file mode 100644
index 0000000..18cc1b7
--- /dev/null
+++ b/pkg/typex/generic.go
@@ -0,0 +1,8 @@
+package typex
+
+import "reflect"
+
+func TypeOf[T any]() reflect.Type {
+	var t T
+	return reflect.TypeOf(t)
+}
diff --git a/pkg/typex/multitype.go b/pkg/typex/multitype.go
index 12ac6c4..a834346 100644
--- a/pkg/typex/multitype.go
+++ b/pkg/typex/multitype.go
@@ -5,12 +5,16 @@ import "reflect"
 type MultiType2[T1, T2 any] struct {
 	obj any
 	t   reflect.Type
+	t1  reflect.Type
+	t2  reflect.Type
 }
 
 func NewMultiType2WithT1[T1, T2 any](obj T1) *MultiType2[T1, T2] {
 	return &MultiType2[T1, T2]{
 		obj: obj,
 		t:   reflect.TypeOf(obj),
+		t1:  TypeOf[T1](),
+		t2:  TypeOf[T2](),
 	}
 }
 
@@ -18,15 +22,17 @@ func NewMultiType2WithT2[T1, T2 any](obj T2) *MultiType2[T1, T2] {
 	return &MultiType2[T1, T2]{
 		obj: obj,
 		t:   reflect.TypeOf(obj),
+		t1:  TypeOf[T1](),
+		t2:  TypeOf[T2](),
 	}
 }
 
 func (m *MultiType2[T1, T2]) IsT1() bool {
-	return m.t == reflect.TypeOf(m.obj)
+	return m.t == m.t1
 }
 
 func (m *MultiType2[T1, T2]) IsT2() bool {
-	return m.t == reflect.TypeOf(m.obj)
+	return m.t == m.t2
 }
 
 func (m *MultiType2[T1, T2]) GetT1() T1 {
@@ -39,10 +45,12 @@ func (m *MultiType2[T1, T2]) GetT2() T2 {
 
 func (m *MultiType2[T1, T2]) SetT1(t T1) {
 	m.obj = t
+	m.t = m.t1
 }
 
 func (m *MultiType2[T1, T2]) SetT2(t T2) {
 	m.obj = t
+	m.t = m.t2
 }
 
 func (m *MultiType2[T1, T2]) Get() any {
@@ -52,12 +60,18 @@ func (m *MultiType2[T1, T2]) Get() any {
 type MultiType3[T1, T2, T3 any] struct {
 	obj any
 	t   reflect.Type
+	t1  reflect.Type
+	t2  reflect.Type
+	t3  reflect.Type
 }
 
 func NewMultiType3WithT1[T1, T2, T3 any](obj T1) *MultiType3[T1, T2, T3] {
 	return &MultiType3[T1, T2, T3]{
 		obj: obj,
 		t:   reflect.TypeOf(obj),
+		t1:  TypeOf[T1](),
+		t2:  TypeOf[T2](),
+		t3:  TypeOf[T3](),
 	}
 }
 
@@ -65,6 +79,9 @@ func NewMultiType3WithT2[T1, T2, T3 any](obj T2) *MultiType3[T1, T2, T3] {
 	return &MultiType3[T1, T2, T3]{
 		obj: obj,
 		t:   reflect.TypeOf(obj),
+		t1:  TypeOf[T1](),
+		t2:  TypeOf[T2](),
+		t3:  TypeOf[T3](),
 	}
 }
 
@@ -72,19 +89,22 @@ func NewMultiType3WithT3[T1, T2, T3 any](obj T3) *MultiType3[T1, T2, T3] {
 	return &MultiType3[T1, T2, T3]{
 		obj: obj,
 		t:   reflect.TypeOf(obj),
+		t1:  TypeOf[T1](),
+		t2:  TypeOf[T2](),
+		t3:  TypeOf[T3](),
 	}
 }
 
 func (m *MultiType3[T1, T2, T3]) IsT1() bool {
-	return m.t == reflect.TypeOf(m.obj)
+	return m.t == m.t1
 }
 
 func (m *MultiType3[T1, T2, T3]) IsT2() bool {
-	return m.t == reflect.TypeOf(m.obj)
+	return m.t == m.t2
 }
 
 func (m *MultiType3[T1, T2, T3]) IsT3() bool {
-	return m.t == reflect.TypeOf(m.obj)
+	return m.t == m.t3
 }
 
 func (m *MultiType3[T1, T2, T3]) GetT1() T1 {
@@ -101,14 +121,18 @@ func (m *MultiType3[T1, T2, T3]) GetT3() T3 {
 
 func (m *MultiType3[T1, T2, T3]) SetT1(t T1) {
 	m.obj = t
+	m.t = m.t1
 }
 
 func (m *MultiType3[T1, T2, T3]) SetT2(t T2) {
 	m.obj = t
+	m.t = m.t2
+
 }
 
 func (m *MultiType3[T1, T2, T3]) SetT3(t T3) {
 	m.obj = t
+	m.t = m.t3
 }
 
 func (m *MultiType3[T1, T2, T3]) Get() any {
diff --git a/pkg/typex/multitype_test.go b/pkg/typex/multitype_test.go
new file mode 100644
index 0000000..198616c
--- /dev/null
+++ b/pkg/typex/multitype_test.go
@@ -0,0 +1,30 @@
+package typex
+
+import (
+	"testing"
+)
+
+func TestMultiType(t *testing.T) {
+	m := NewMultiType2WithT1[double, string](1)
+	if !m.IsT1() {
+		t.Errorf("IsT1 failed")
+		t.Fail()
+	}
+	if m.IsT2() {
+		t.Errorf("IsT2 failed")
+		t.Fail()
+	}
+	m.SetT2("hello")
+	if !m.IsT2() {
+		t.Errorf("IsT2 failed")
+		t.Fail()
+	}
+	if m.IsT1() {
+		t.Errorf("IsT1 failed")
+		t.Fail()
+	}
+	if m.GetT2() != "hello" {
+		t.Errorf("GetT2 failed")
+		t.Fail()
+	}
+}
diff --git a/pkg/typex/num.go b/pkg/typex/num.go
index 7662197..3c4b415 100644
--- a/pkg/typex/num.go
+++ b/pkg/typex/num.go
@@ -10,3 +10,4 @@ type u32 uint32
 type u64 uint64
 type f32 float32
 type f64 float64
+type double float64