detail error message on RegisterStructValidationCtx finding pointer arg

validator_instance.go

@@ -210,7 +210,9 @@ func (v *Validate) RegisterStructValidationCtx(fn StructLevelFuncCtx, types ...i
 
 	for _, t := range types {
 		if reflect.ValueOf(t).Kind() == reflect.Ptr {
-			return fmt.Errorf("error")
+			return fmt.Errorf(
+				"Type must be a non-pointer, %s is a pointer",
+				reflect.TypeOf(t))
 		}
 	}
 

validator_test.go

@@ -8154,6 +8154,8 @@ func TestStructLevelValidationsPointerPassing(t *testing.T) {
 	v1 := New()
 	err1 := v1.RegisterStructValidation(StructValidationTestStruct, &TestStruct{})
 	NotEqual(t, err1, nil)
+	Equal(t, err1.Error(),
+		"Type must be a non-pointer, *validator.TestStruct is a pointer")
 
 	v2 := New()
 	err2 := v2.RegisterStructValidation(StructValidationTestStruct, TestStruct{})