Reentrancy modifier questions

[deuszx]

Given the code https://github.com/Brushfam/openbrush-contracts/blob/main/contracts/src/security/reentrancy_guard/mod.rs#L56

I have the following questions:

Should we really require the whole T: Storable bound on:

T: Storage<Data> + Storable

given that what we store is not T but Data:

    ink::env::set_contract_storage::<Key, Data>(&Default::default(), &instance.data());

---

And secondly, is Default::default() key safe to use in

ink::env::set_contract_storage::<Key, Data>(&Default::default(), &instance.data());

Key type here is ink::primitives::Key type (u32 alias) and defaults to 0. It could mean that if some other part of the contract, tries to store anything under that key (0) then it overwrites the instance.data(). Or vice versa - instance.data() may overwrite anything that was already stored there.