https://eips.ethereum.org/EIP...

Abstract

以下规范容许为代表单个底层 ERC-20 份额的保险库施行规范 API。 该规范是 ERC-20 代币的扩大，它提供了存取代币和读取余额的基本功能。

Motivation

代币化保险库不足标准化，导致施行细节多样化。 一些不同的例子包含借贷市场、聚合器和具备外在利息的代币。 这使得须要合乎许多规范的协定在聚合器或插件层难以集成，并迫使每个协定实现本人的适配器，这些适配器容易出错并节约开发资源。代币化保险库的规范将升高收益保险库的集成工作量，同时创立更加统一和弱小的施行模式。

Code

Events

Deposit事件：

event Deposit(address indexed caller, address indexed owner, uint256 assets, uint256 shares);

Withdraw事件:

event Withdraw(        address indexed caller,        address indexed receiver,        address indexed owner,        uint256 assets,        uint256 shares);

IMMUTABLES

ERC20 public immutable asset;constructor(    ERC20 _asset,    string memory _name,    string memory _symbol) ERC20(_name, _symbol, _asset.decimals()) {    asset = _asset;}

Main Logic

Deposit函数：function deposit(uint256 assets, address receiver) public virtual returns (uint256 shares) {    // Check for rounding error since we round down in previewDeposit.    require((shares = previewDeposit(assets)) != 0, "ZERO_SHARES");    // Need to transfer before minting or ERC777s could reenter.    asset.safeTransferFrom(msg.sender, address(this), assets);    _mint(receiver, shares);    emit Deposit(msg.sender, receiver, assets, shares);    afterDeposit(assets, shares);}

Mint函数：

function mint(uint256 shares, address receiver) public virtual returns (uint256 assets) {    assets = previewMint(shares); // No need to check for rounding error, previewMint rounds up.    // Need to transfer before minting or ERC777s could reenter.    asset.safeTransferFrom(msg.sender, address(this), assets);    _mint(receiver, shares);    emit Deposit(msg.sender, receiver, assets, shares);    afterDeposit(assets, shares);}

Withdraw函数:

function withdraw(    uint256 assets,    address receiver,    address owner) public virtual returns (uint256 shares) {    shares = previewWithdraw(assets); // No need to check for rounding error, previewWithdraw rounds up.    if (msg.sender != owner) {        uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.        if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;    }    beforeWithdraw(assets, shares);    _burn(owner, shares);    emit Withdraw(msg.sender, receiver, owner, assets, shares);    asset.safeTransfer(receiver, assets);}

Redeem函数：

function redeem(    uint256 shares,    address receiver,    address owner) public virtual returns (uint256 assets) {    if (msg.sender != owner) {        uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.        if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;    }    // Check for rounding error since we round down in previewRedeem.    require((assets = previewRedeem(shares)) != 0, "ZERO_ASSETS");    beforeWithdraw(assets, shares);    _burn(owner, shares);    emit Withdraw(msg.sender, receiver, owner, assets, shares);    asset.safeTransfer(receiver, assets);}

Account Logic

function totalAssets() public view virtual returns (uint256);function convertToShares(uint256 assets) public view returns (uint256) {    uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.    return supply == 0 ? assets : assets.mulDivDown(supply, totalAssets());}function convertToAssets(uint256 shares) public view returns (uint256) {    uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.    return supply == 0 ? shares : shares.mulDivDown(totalAssets(), supply);}function previewDeposit(uint256 assets) public view virtual returns (uint256) {    return convertToShares(assets);}function previewMint(uint256 shares) public view virtual returns (uint256) {    uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.    return supply == 0 ? shares : shares.mulDivUp(totalAssets(), supply);}function previewWithdraw(uint256 assets) public view virtual returns (uint256) {    uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.    return supply == 0 ? assets : assets.mulDivUp(supply, totalAssets());}function previewRedeem(uint256 shares) public view virtual returns (uint256) {    return convertToAssets(shares);}/*///////////////////////////////////////////////////////////////                 DEPOSIT/WITHDRAWAL LIMIT LOGIC//////////////////////////////////////////////////////////////*/function maxDeposit(address) public view virtual returns (uint256) {    return type(uint256).max;}function maxMint(address) public view virtual returns (uint256) {    return type(uint256).max;}function maxWithdraw(address owner) public view virtual returns (uint256) {    return convertToAssets(balanceOf[owner]);}function maxRedeem(address owner) public view virtual returns (uint256) {    return balanceOf[owner];}

Hooks Logic

function beforeWithdraw(uint256 assets, uint256 shares) internal virtual {}function afterDeposit(uint256 assets, uint256 shares) internal virtual {}

参考文章

https://ethereum-magicians.or...
https://github.com/Rari-Capit...