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BasicShareManager

Overview​

BasicShareManager is a concrete implementation of the abstract ShareManager, designed to provide native ERC20 style share accounting within a modular vault system. It handles minting, burning, locking, and balance accounting of vault shares directly through a local ERC20 compatible storage layout, without exposing standard ERC20 interfaces.

This contract is intended for setups where shares are not tokenized on-chain as ERC20s but are still tracked internally using the ERC20Upgradeable storage schema.

Key Features​

  • Uses ShareManager for permissioning, allocation, and whitelisting logic.
  • Maintains balances and total supply using ERC20Upgradeable.ERC20Storage.
  • Internal mint and burn logic emits IERC20.Transfer events (for transparency or compatibility).
  • Fully decoupled from standard ERC20 interface. Share movements use vault queues and the internal mint, burn, and lock paths.

Configuration and State​

Storage​

ERC20 style balances and supply are stored at a fixed storage slot allowing for migrations between BasicShareManager and TokenizedShareManager:

bytes32 private constant ERC20StorageLocation = 0x52c6...ce00;

Initialization​

function initialize(bytes calldata data) external initializer
  • Expects a single bytes32 whitelistMerkleRoot (used by ShareManager).

Functions​

View Functions​

  • activeShares(): Returns _totalSupply from ERC20 storage.
  • activeSharesOf(account): Returns balance of account.

Internal Logic​

_mintShares(address, uint256)​

  • Checks if minting is allowed via updateChecks.
  • Increments total supply and receiver's balance.
  • Emits IERC20.Transfer(address(0), account, value).

Reverts if:

  • account == address(0).
  • Minting is paused, or the account fails the whitelist or blacklist checks. The global lockup does not block minting.

_burnShares(address, uint256)​

  • Checks if burning is allowed via updateChecks.
  • Decreases sender's balance and total supply.
  • Emits IERC20.Transfer(account, address(0), value).

Reverts if:

  • account == address(0).
  • value > account balance.
  • Burning is paused or blocked.

_lockShares(address, uint256)​

Applies burn checks to the account, then moves its shares to the manager without changing total supply. It emits IERC20.Transfer(account, address(this), value). The account must be non-zero and its balance must cover the amount.

Invariants and Limitations​

Design Notes​

  • This module deliberately avoids exposing the ERC20 interface, preventing unintended external transfers or integrations.
  • It is intended for internal share accounting within vault systems, where shares are tracked but not tokenized on-chain.
  • All permissioning logic, including minting, burning, whitelisting, and lockup enforcement, is delegated to the inherited ShareManager.
  • This implementation is ideal when the vault owner requires non-transferable shares for internal logic, without compliance to ERC20 or ERC4626 standards.
  • It is not appropriate for setups where shares must be externally transferable, interoperable with third-party protocols, or conform to token standards.