diff --git a/src/obj_anywhere/DataStore.hpp b/src/obj_anywhere/DataStore.hpp
index 2035d63..ad8fc5b 100644
--- a/src/obj_anywhere/DataStore.hpp
+++ b/src/obj_anywhere/DataStore.hpp
@@ -16,7 +16,6 @@
 // ***********************************************************************************************
 #pragma once
 
-#include <string>
 #include <unordered_map>
 
 #include "SafePtr.hpp"  // can't UniPtr.hpp since ut(=req) build-err
@@ -26,26 +25,26 @@ using namespace std;
 
 namespace RLib
 {
-using DataKey = string;
-
 // ***********************************************************************************************
+template<typename aDataKey>
 class DataStore
 {
 public:
-    template<typename aDataT> SafePtr<aDataT> get(const DataKey& aKey) const;
-    void set(const DataKey& aKey, SafePtr<void> aData);
+    template<typename aDataT> SafePtr<aDataT> get(const aDataKey& aKey) const;
+    void set(const aDataKey& aKey, SafePtr<void> aData);
     size_t nData() const { return key_data_S_.size(); }
 
     ~DataStore() { HID("(DataStore) discard nData=" << nData()); }  // debug
 
 private:
     // -------------------------------------------------------------------------------------------
-    unordered_map<DataKey, SafePtr<void>> key_data_S_;
+    unordered_map<aDataKey, SafePtr<void>> key_data_S_;
 };
 
 // ***********************************************************************************************
+template<typename aDataKey>
 template<typename aDataT>
-SafePtr<aDataT> DataStore::get(const DataKey& aKey) const
+SafePtr<aDataT> DataStore<aDataKey>::get(const aDataKey& aKey) const
 {
     auto&& key_data = key_data_S_.find(aKey);
     if (key_data == key_data_S_.end())
@@ -57,8 +56,8 @@ SafePtr<aDataT> DataStore::get(const DataKey& aKey) const
 }
 
 // ***********************************************************************************************
-inline
-void DataStore::set(const DataKey& aKey, SafePtr<void> aData)
+template<typename aDataKey>
+void DataStore<aDataKey>::set(const aDataKey& aKey, SafePtr<void> aData)
 {
     if (aData.get() == nullptr)
     {
@@ -67,8 +66,8 @@ void DataStore::set(const DataKey& aKey, SafePtr<void> aData)
     }
     else
     {
-        HID("(DataStore) new/replace key=" << aKey);
-        key_data_S_[aKey] = aData;
+        auto&& it_ok = key_data_S_.emplace(aKey, aData);
+        if (it_ok.second == false) { HID("(DataStore) ERR!!! not support to replace key=" << aKey); }
     }
 }
 
diff --git a/src/obj_anywhere/ObjAnywhere.cpp b/src/obj_anywhere/ObjAnywhere.cpp
index 83093b0..d3fd682 100644
--- a/src/obj_anywhere/ObjAnywhere.cpp
+++ b/src/obj_anywhere/ObjAnywhere.cpp
@@ -7,7 +7,7 @@
 
 namespace RLib
 {
-shared_ptr<DataStore> ObjAnywhere::name_obj_S_;
+shared_ptr<DataStore<ObjName>> ObjAnywhere::name_obj_S_;
 
 // ***********************************************************************************************
 void ObjAnywhere::deinit()
@@ -24,7 +24,7 @@ void ObjAnywhere::init(UniLog& oneLog)
     else
     {
         HID("(ObjAnywhere) Succeed.");
-        name_obj_S_ = make_shared<DataStore>();
+        name_obj_S_ = make_shared<DataStore<ObjName>>();
     }
 }
 }  // namespace
diff --git a/src/obj_anywhere/ObjAnywhere.hpp b/src/obj_anywhere/ObjAnywhere.hpp
index 79b09ac..cd3c7d6 100644
--- a/src/obj_anywhere/ObjAnywhere.hpp
+++ b/src/obj_anywhere/ObjAnywhere.hpp
@@ -32,6 +32,8 @@
 // ***********************************************************************************************
 #pragma once
 
+#include <string>
+
 #include "DataStore.hpp"
 #include "UniLog.hpp"
 
@@ -39,6 +41,8 @@ using namespace std;
 
 namespace RLib
 {
+using ObjName = string;
+
 // ***********************************************************************************************
 class ObjAnywhere
 {
@@ -50,18 +54,18 @@ class ObjAnywhere
 
     // typeid().name() is to compatible with previous interface (w/o aObjName), eg ::get<TypeParam>
     template<typename aObjType> static
-    void setObj(SafePtr<aObjType>, UniLog& = UniLog::defaultUniLog_, const DataKey& = typeid(aObjType).name());
+    void setObj(SafePtr<aObjType>, UniLog& = UniLog::defaultUniLog_, const ObjName& = typeid(aObjType).name());
     template<typename aObjType> static
-    SafePtr<aObjType> getObj(const DataKey& = typeid(aObjType).name());
+    SafePtr<aObjType> getObj(const ObjName& = typeid(aObjType).name());
 
 private:
     // -------------------------------------------------------------------------------------------
-    static shared_ptr<DataStore> name_obj_S_;  // store aObj w/o include aObj.hpp
+    static shared_ptr<DataStore<ObjName>> name_obj_S_;  // store aObj w/o include aObj.hpp
 };
 
 // ***********************************************************************************************
 template<typename aObjType>
-SafePtr<aObjType> ObjAnywhere::getObj(const DataKey& aObjName)
+SafePtr<aObjType> ObjAnywhere::getObj(const ObjName& aObjName)
 {
     if (isInit())
         return name_obj_S_->get<aObjType>(aObjName);
@@ -70,7 +74,7 @@ SafePtr<aObjType> ObjAnywhere::getObj(const DataKey& aObjName)
 
 // ***********************************************************************************************
 template<typename aObjType>
-void ObjAnywhere::setObj(SafePtr<aObjType> aObj, UniLog& oneLog, const DataKey& aObjName)
+void ObjAnywhere::setObj(SafePtr<aObjType> aObj, UniLog& oneLog, const ObjName& aObjName)
 {
     if (isInit())
         name_obj_S_->set(aObjName, aObj);
diff --git a/ut/obj_anywhere/DataStoreTest.cpp b/ut/obj_anywhere/DataStoreTest.cpp
index c8e22af..ca0ac4e 100644
--- a/ut/obj_anywhere/DataStoreTest.cpp
+++ b/ut/obj_anywhere/DataStoreTest.cpp
@@ -5,6 +5,7 @@
 */
 // ***********************************************************************************************
 #include <gtest/gtest.h>
+#include <string>
 #include <type_traits>
 
 #include "DataStore.hpp"
@@ -17,7 +18,7 @@ namespace RLib
 // ***********************************************************************************************
 struct DataStoreTest : public Test
 {
-    DataStore dataStore_;
+    DataStore<string> dataStore_;
 };
 
 #define STORE
@@ -59,6 +60,16 @@ TEST_F(DataStoreTest, noNeedToStoreNull)
     dataStore_.set("string", nullptr);
     EXPECT_EQ(0u, dataStore_.nData()) << "REQ: erase OK";
 }
+TEST_F(DataStoreTest, replace)
+{
+    dataStore_.set("string", make_safe<string>("hello"));
+    dataStore_.set("string", make_safe<string>("world"));
+    EXPECT_EQ("hello", *(dataStore_.get<string>("string").get())) << "req: refuse replace";
+
+    dataStore_.set("string", nullptr);
+    dataStore_.set("string", make_safe<string>("world"));
+    EXPECT_EQ("world", *(dataStore_.get<string>("string").get())) << "req: explicit rm then set ok";
+}
 
 #define SAFE
 // ***********************************************************************************************
diff --git a/ut/obj_anywhere/ObjAnywhereTest.cpp b/ut/obj_anywhere/ObjAnywhereTest.cpp
index 6b2a340..e39d4f1 100644
--- a/ut/obj_anywhere/ObjAnywhereTest.cpp
+++ b/ut/obj_anywhere/ObjAnywhereTest.cpp
@@ -44,7 +44,11 @@ TEST_F(ObjAnywhereTest, get_replacement)
     ObjAnywhere::setObj(p1, *this);
     auto p2 = make_safe<int>(2);
     ObjAnywhere::setObj(p2, *this);  // req: replace set
-    EXPECT_EQ(p2.get(), ObjAnywhere::getObj<int>().get()) << "REQ: get p2 itself";
+    EXPECT_EQ(p1.get(), ObjAnywhere::getObj<int>().get()) << "REQ: refuse replacement";
+
+    ObjAnywhere::setObj<int>(nullptr, *this);
+    ObjAnywhere::setObj(p2, *this);
+    EXPECT_EQ(p2.get(), ObjAnywhere::getObj<int>().get()) << "REQ: explicit rm then set ok";
     ObjAnywhere::deinit();
 }
 TEST_F(ObjAnywhereTest, noSet_getNull)