Why is impossible to reuse mapping key at mapping(uint256=>EnumberableSet.AddressSet)?

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1

I've defined one state variable called data that has mapping(uint256=>EnumberableSet.AddressSet),
according to the requirements, I've deleted item like this.
delete data[0]

after delete, if I try to add one variable again with this key -> 0
data[0].add(msg.sender), no runtime error but happened nothing at variable data.
it maintain original values and don't save.
If faced on such trouble past time, could kindly teach me to solve this?
best.

2

You can't use delete with EnumerableSet. Please use data[0].clear().

3

clear function is not defined. I've just checked recent version also in openzeppelin repo.
so I've made myself wrapper just and working well.
thanks for your reply.
best.

4
5

Sorry I thought we had a clear function. I remember now that we don't.

You still shouldn't delete enumerable sets and maps. You should use a fresh instance at a fresh location if you need to reset it.

See the warning in the docs.

1 Like
6

Yeah so based on that, I've made wrapper. working well. no worries.

7

Ok! Please share the wrapper, it sounds like it could be useful for others.

8 
library SetUpgradeable {
 struct AddressSet {
   uint256 id;
   mapping(uint256 => EnumerableSetUpgradeable.AddressSet) sets;
 }
 function clear(AddressSet storage data) internal {
   uint256 id= data.Id;
   delete data._addressSets[Id];
   data.id += 1;
 }
}
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