@ -2,14 +2,36 @@
### Removals
The following contracts and librarie s were removed:
The following contracts, libraries and function s were removed:
- `Address.isContract` (because of its ambiguous nature and potential for misuse)
- `Checkpoints.History`
- `Counters`
- `ERC20Snapshot`
- `ERC20VotesComp`
- `ERC165Storage` (in favor of inheritance based approach)
- `ERC777`
- `ERC1820Implementer`
- `GovernorVotesComp`
- `GovernorProposalThreshold` (deprecated since 4.4)
- `PaymentSplitter`
- `TokenTimelock` (removed in favor of `VestingWallet` )
- `PullPayment`
- `SafeMath`
- `SignedSafeMath`
- `Timers`
- `TokenTimelock` (in favor of `VestingWallet` )
- All escrow contracts (`Escrow`, `ConditionalEscrow` and `RefundEscrow` )
- All cross-chain contracts, including `AccessControlCrossChain` and all the vendored bridge interfaces
- All presets in favor of [OpenZeppelin Contracts Wizard ](https://wizard.openzeppelin.com/ )
These removals were implemented in the following PRs:
- [3637 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3637 )
- [3880 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3880 )
- [3945 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3945 )
- [4258 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4258 )
- [4276 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4276 )
- [4289 ](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4289 )
### How to upgrade from 4.x