Fixed ComponentWrapper string scope error

include/Engine/Core/ComponentWrapper.h

@@ -37,13 +37,13 @@ struct ComponentWrapper
     {
         friend struct ComponentWrapper;
     private:
-        SubscriptProxy(ComponentWrapper* component, std::string& propertyName)
+        SubscriptProxy(ComponentWrapper* component, std::string propertyName)
             : m_Component(component)
             , m_PropertyName(propertyName)
         { }
 
         ComponentWrapper* m_Component;
-        std::string& m_PropertyName;
+        std::string m_PropertyName;
 
     public:
         template <typename T>

src/Tests/ComponentPoolTest.cpp

@@ -22,8 +22,7 @@ BOOST_AUTO_TEST_CASE(ComponentPoolTest)
     int i = 0;
     for (auto& c : pool) {
         BOOST_CHECK(c.EntityID == i);
-        int field = c.Property<int>("Field");
-        BOOST_CHECK(field == i);
+        BOOST_CHECK((int)c["Field"] == i);
         i++;
     }
 }