Is zeroing user or lib responsibility

I’m making a core password manager/vault library, and I’m wondering whether I should zero the memory or the user should do this. One way they could do this is through a ZeroingAllocator, which std.crypto.secureZero’s all memory that is freed. This also makes it easier for me because I have a StringHashMap where the keys need to be freed, and the allocators already @constCast. Two problems with this: User doesn’t know about having to do this. User would prefer not to worry about it and have t...