openzeppelin

Inherit from ERC20 and call _mint in the constructor with the desired supply. For extensions like Permit or Votes, add the inheritance and resolve the _update and nonces overrides explicitly, since v5 requires diamond resolution when combining ERC20Permit with ERC20Votes.

Pass an initial owner to the Ownable constructor, replace _setupRole with _grantRole, replace _beforeTokenTransfer with _update, remove SafeMath and Counters, and move Pausable and ReentrancyGuard imports from security/ to utils/. ERC721Enumerable also requires a new _increaseBalance override.

OpenZeppelin v5 removed the default owner, so Ownable requires an initial owner address passed to its constructor. Write constructor(address initialOwner) Ownable(initialOwner) instead of inheriting Ownable with no arguments.

Use the contracts-upgradeable package with Initializable, UUPSUpgradeable, and an initialize function instead of a constructor. Deploy an ERC1967Proxy pointing to the implementation, gate _authorizeUpgrade with onlyOwner, and use reinitializer(n) for version-specific setup in later upgrades.

No, both were removed in v5. Solidity 0.8+ has built-in overflow checks making SafeMath unnecessary, and Counters was replaced by plain uint256 variables with the ++ operator.

OpenZeppelin v5 requires overriding both _update and _increaseBalance when combining ERC721 with ERC721Enumerable. Add both overrides calling super, and list all parent contracts in the override specifier.