There is also the approach of using an Array or Map (Which allows for a custom ID, ie Key type) and place that in a Global variable like the GameInstance or the GameState. This is what I am currently using in one of my games, to store data about certain items, the Key is the Item’s class (which means I can easily retrieve data at runtime using classes) and the Value is a Struct that defines said item. I can easily access the Map, can use it for saving and loading, and for pre-defining data.
Basically a Map where:
Map
EDIT: Oups, sorry for posting on an old question.