Storage

// ❌ DANGEROUS: Storage collision risk
contract ProxyV1 {
  uint256 value;        // slot 0
  address owner;        // slot 1
}

contract ProxyV2 {
  address newOwner;     // slot 0 - COLLISION!
  uint256 value;        // slot 1 - COLLISION!
}

// ✅ SAFE: Isolated namespaced storage
contract ProxyV1 {
  struct V1Storage {
    uint256 value;
    address owner;
  }

  function getStorage() internal pure returns (V1Storage storage $) {
    assembly {
      $.slot := 0xabcd... // ERC-7201 slot
    }
  }
}

contract ProxyV2 {
  struct V2Storage {
    address newOwner;
    uint256 value;
  }

  function getStorage() internal pure returns (V2Storage storage $) {
    assembly {
      $.slot := 0x1234... // Different ERC-7201 slot
    }
  }
}