Description:
Multi-signature wallet contract requiring multiple confirmations for transaction execution.
Blockchain: Ethereum
Source Code: View Code On The Blockchain
Solidity Source Code:
{{
"language": "Solidity",
"sources": {
"src/finance/oracles/ERC4626Oracle.sol": {
"content": "// SPDX-License-Identifier: MIT
pragma solidity 0.8.28;
import {ERC4626} from "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
import {FixedPointMathLib} from "@solmate/src/utils/FixedPointMathLib.sol";
import {IOracle} from "@interfaces/IOracle.sol";
/// @notice Returns the price of an ERC4626 vault share token, in $ with 18 decimals.
contract ERC4626Oracle is IOracle {
using FixedPointMathLib for uint256;
address public immutable vault;
address public immutable assetOracle;
constructor(address _vault, address _assetOracle) {
vault = _vault;
assetOracle = _assetOracle;
}
function price() external view override returns (uint256) {
uint256 assetPrice = IOracle(assetOracle).price();
uint256 sharePrice = ERC4626(vault).convertToAssets(FixedPointMathLib.WAD);
return sharePrice.mulWadDown(assetPrice);
}
}
"
},
"lib/openzeppelin-contracts/contracts/token/ERC20/extensions/ERC4626.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/ERC4626.sol)
pragma solidity ^0.8.20;
import {IERC20, IERC20Metadata, ERC20} from "../ERC20.sol";
import {SafeERC20} from "../utils/SafeERC20.sol";
import {IERC4626} from "../../../interfaces/IERC4626.sol";
import {Math} from "../../../utils/math/Math.sol";
/**
* @dev Implementation of the ERC-4626 "Tokenized Vault Standard" as defined in
* https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
*
* This extension allows the minting and burning of "shares" (represented using the ERC-20 inheritance) in exchange for
* underlying "assets" through standardized {deposit}, {mint}, {redeem} and {burn} workflows. This contract extends
* the ERC-20 standard. Any additional extensions included along it would affect the "shares" token represented by this
* contract and not the "assets" token which is an independent contract.
*
* [CAUTION]
* ====
* In empty (or nearly empty) ERC-4626 vaults, deposits are at high risk of being stolen through frontrunning
* with a "donation" to the vault that inflates the price of a share. This is variously known as a donation or inflation
* attack and is essentially a problem of slippage. Vault deployers can protect against this attack by making an initial
* deposit of a non-trivial amount of the asset, such that price manipulation becomes infeasible. Withdrawals may
* similarly be affected by slippage. Users can protect against this attack as well as unexpected slippage in general by
* verifying the amount received is as expected, using a wrapper that performs these checks such as
* https://github.com/fei-protocol/ERC4626#erc4626router-and-base[ERC4626Router].
*
* Since v4.9, this implementation introduces configurable virtual assets and shares to help developers mitigate that risk.
* The `_decimalsOffset()` corresponds to an offset in the decimal representation between the underlying asset's decimals
* and the vault decimals. This offset also determines the rate of virtual shares to virtual assets in the vault, which
* itself determines the initial exchange rate. While not fully preventing the attack, analysis shows that the default
* offset (0) makes it non-profitable even if an attacker is able to capture value from multiple user deposits, as a result
* of the value being captured by the virtual shares (out of the attacker's donation) matching the attacker's expected gains.
* With a larger offset, the attack becomes orders of magnitude more expensive than it is profitable. More details about the
* underlying math can be found xref:ROOT:erc4626.adoc#inflation-attack[here].
*
* The drawback of this approach is that the virtual shares do capture (a very small) part of the value being accrued
* to the vault. Also, if the vault experiences losses, the users try to exit the vault, the virtual shares and assets
* will cause the first user to exit to experience reduced losses in detriment to the last users that will experience
* bigger losses. Developers willing to revert back to the pre-v4.9 behavior just need to override the
* `_convertToShares` and `_convertToAssets` functions.
*
* To learn more, check out our xref:ROOT:erc4626.adoc[ERC-4626 guide].
* ====
*/
abstract contract ERC4626 is ERC20, IERC4626 {
using Math for uint256;
IERC20 private immutable _asset;
uint8 private immutable _underlyingDecimals;
/**
* @dev Attempted to deposit more assets than the max amount for `receiver`.
*/
error ERC4626ExceededMaxDeposit(address receiver, uint256 assets, uint256 max);
/**
* @dev Attempted to mint more shares than the max amount for `receiver`.
*/
error ERC4626ExceededMaxMint(address receiver, uint256 shares, uint256 max);
/**
* @dev Attempted to withdraw more assets than the max amount for `receiver`.
*/
error ERC4626ExceededMaxWithdraw(address owner, uint256 assets, uint256 max);
/**
* @dev Attempted to redeem more shares than the max amount for `receiver`.
*/
error ERC4626ExceededMaxRedeem(address owner, uint256 shares, uint256 max);
/**
* @dev Set the underlying asset contract. This must be an ERC20-compatible contract (ERC-20 or ERC-777).
*/
constructor(IERC20 asset_) {
(bool success, uint8 assetDecimals) = _tryGetAssetDecimals(asset_);
_underlyingDecimals = success ? assetDecimals : 18;
_asset = asset_;
}
/**
* @dev Attempts to fetch the asset decimals. A return value of false indicates that the attempt failed in some way.
*/
function _tryGetAssetDecimals(IERC20 asset_) private view returns (bool ok, uint8 assetDecimals) {
(bool success, bytes memory encodedDecimals) = address(asset_).staticcall(
abi.encodeCall(IERC20Metadata.decimals, ())
);
if (success && encodedDecimals.length >= 32) {
uint256 returnedDecimals = abi.decode(encodedDecimals, (uint256));
if (returnedDecimals <= type(uint8).max) {
return (true, uint8(returnedDecimals));
}
}
return (false, 0);
}
/**
* @dev Decimals are computed by adding the decimal offset on top of the underlying asset's decimals. This
* "original" value is cached during construction of the vault contract. If this read operation fails (e.g., the
* asset has not been created yet), a default of 18 is used to represent the underlying asset's decimals.
*
* See {IERC20Metadata-decimals}.
*/
function decimals() public view virtual override(IERC20Metadata, ERC20) returns (uint8) {
return _underlyingDecimals + _decimalsOffset();
}
/** @dev See {IERC4626-asset}. */
function asset() public view virtual returns (address) {
return address(_asset);
}
/** @dev See {IERC4626-totalAssets}. */
function totalAssets() public view virtual returns (uint256) {
return IERC20(asset()).balanceOf(address(this));
}
/** @dev See {IERC4626-convertToShares}. */
function convertToShares(uint256 assets) public view virtual returns (uint256) {
return _convertToShares(assets, Math.Rounding.Floor);
}
/** @dev See {IERC4626-convertToAssets}. */
function convertToAssets(uint256 shares) public view virtual returns (uint256) {
return _convertToAssets(shares, Math.Rounding.Floor);
}
/** @dev See {IERC4626-maxDeposit}. */
function maxDeposit(address) public view virtual returns (uint256) {
return type(uint256).max;
}
/** @dev See {IERC4626-maxMint}. */
function maxMint(address) public view virtual returns (uint256) {
return type(uint256).max;
}
/** @dev See {IERC4626-maxWithdraw}. */
function maxWithdraw(address owner) public view virtual returns (uint256) {
return _convertToAssets(balanceOf(owner), Math.Rounding.Floor);
}
/** @dev See {IERC4626-maxRedeem}. */
function maxRedeem(address owner) public view virtual returns (uint256) {
return balanceOf(owner);
}
/** @dev See {IERC4626-previewDeposit}. */
function previewDeposit(uint256 assets) public view virtual returns (uint256) {
return _convertToShares(assets, Math.Rounding.Floor);
}
/** @dev See {IERC4626-previewMint}. */
function previewMint(uint256 shares) public view virtual returns (uint256) {
return _convertToAssets(shares, Math.Rounding.Ceil);
}
/** @dev See {IERC4626-previewWithdraw}. */
function previewWithdraw(uint256 assets) public view virtual returns (uint256) {
return _convertToShares(assets, Math.Rounding.Ceil);
}
/** @dev See {IERC4626-previewRedeem}. */
function previewRedeem(uint256 shares) public view virtual returns (uint256) {
return _convertToAssets(shares, Math.Rounding.Floor);
}
/** @dev See {IERC4626-deposit}. */
function deposit(uint256 assets, address receiver) public virtual returns (uint256) {
uint256 maxAssets = maxDeposit(receiver);
if (assets > maxAssets) {
revert ERC4626ExceededMaxDeposit(receiver, assets, maxAssets);
}
uint256 shares = previewDeposit(assets);
_deposit(_msgSender(), receiver, assets, shares);
return shares;
}
/** @dev See {IERC4626-mint}. */
function mint(uint256 shares, address receiver) public virtual returns (uint256) {
uint256 maxShares = maxMint(receiver);
if (shares > maxShares) {
revert ERC4626ExceededMaxMint(receiver, shares, maxShares);
}
uint256 assets = previewMint(shares);
_deposit(_msgSender(), receiver, assets, shares);
return assets;
}
/** @dev See {IERC4626-withdraw}. */
function withdraw(uint256 assets, address receiver, address owner) public virtual returns (uint256) {
uint256 maxAssets = maxWithdraw(owner);
if (assets > maxAssets) {
revert ERC4626ExceededMaxWithdraw(owner, assets, maxAssets);
}
uint256 shares = previewWithdraw(assets);
_withdraw(_msgSender(), receiver, owner, assets, shares);
return shares;
}
/** @dev See {IERC4626-redeem}. */
function redeem(uint256 shares, address receiver, address owner) public virtual returns (uint256) {
uint256 maxShares = maxRedeem(owner);
if (shares > maxShares) {
revert ERC4626ExceededMaxRedeem(owner, shares, maxShares);
}
uint256 assets = previewRedeem(shares);
_withdraw(_msgSender(), receiver, owner, assets, shares);
return assets;
}
/**
* @dev Internal conversion function (from assets to shares) with support for rounding direction.
*/
function _convertToShares(uint256 assets, Math.Rounding rounding) internal view virtual returns (uint256) {
return assets.mulDiv(totalSupply() + 10 ** _decimalsOffset(), totalAssets() + 1, rounding);
}
/**
* @dev Internal conversion function (from shares to assets) with support for rounding direction.
*/
function _convertToAssets(uint256 shares, Math.Rounding rounding) internal view virtual returns (uint256) {
return shares.mulDiv(totalAssets() + 1, totalSupply() + 10 ** _decimalsOffset(), rounding);
}
/**
* @dev Deposit/mint common workflow.
*/
function _deposit(address caller, address receiver, uint256 assets, uint256 shares) internal virtual {
// If asset() is ERC-777, `transferFrom` can trigger a reentrancy BEFORE the transfer happens through the
// `tokensToSend` hook. On the other hand, the `tokenReceived` hook, that is triggered after the transfer,
// calls the vault, which is assumed not malicious.
//
// Conclusion: we need to do the transfer before we mint so that any reentrancy would happen before the
// assets are transferred and before the shares are minted, which is a valid state.
// slither-disable-next-line reentrancy-no-eth
SafeERC20.safeTransferFrom(IERC20(asset()), caller, address(this), assets);
_mint(receiver, shares);
emit Deposit(caller, receiver, assets, shares);
}
/**
* @dev Withdraw/redeem common workflow.
*/
function _withdraw(
address caller,
address receiver,
address owner,
uint256 assets,
uint256 shares
) internal virtual {
if (caller != owner) {
_spendAllowance(owner, caller, shares);
}
// If asset() is ERC-777, `transfer` can trigger a reentrancy AFTER the transfer happens through the
// `tokensReceived` hook. On the other hand, the `tokensToSend` hook, that is triggered before the transfer,
// calls the vault, which is assumed not malicious.
//
// Conclusion: we need to do the transfer after the burn so that any reentrancy would happen after the
// shares are burned and after the assets are transferred, which is a valid state.
_burn(owner, shares);
SafeERC20.safeTransfer(IERC20(asset()), receiver, assets);
emit Withdraw(caller, receiver, owner, assets, shares);
}
function _decimalsOffset() internal view virtual returns (uint8) {
return 0;
}
}
"
},
"lib/solmate/src/utils/FixedPointMathLib.sol": {
"content": "// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;
/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/FixedPointMathLib.sol)
/// @author Inspired by USM (https://github.com/usmfum/USM/blob/master/contracts/WadMath.sol)
library FixedPointMathLib {
/*//////////////////////////////////////////////////////////////
SIMPLIFIED FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
uint256 internal constant MAX_UINT256 = 2**256 - 1;
uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.
function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
}
function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
}
function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
}
function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
}
/*//////////////////////////////////////////////////////////////
LOW LEVEL FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
function mulDivDown(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
revert(0, 0)
}
// Divide x * y by the denominator.
z := div(mul(x, y), denominator)
}
}
function mulDivUp(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
revert(0, 0)
}
// If x * y modulo the denominator is strictly greater than 0,
// 1 is added to round up the division of x * y by the denominator.
z := add(gt(mod(mul(x, y), denominator), 0), div(mul(x, y), denominator))
}
}
function rpow(
uint256 x,
uint256 n,
uint256 scalar
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
switch x
case 0 {
switch n
case 0 {
// 0 ** 0 = 1
z := scalar
}
default {
// 0 ** n = 0
z := 0
}
}
default {
switch mod(n, 2)
case 0 {
// If n is even, store scalar in z for now.
z := scalar
}
default {
// If n is odd, store x in z for now.
z := x
}
// Shifting right by 1 is like dividing by 2.
let half := shr(1, scalar)
for {
// Shift n right by 1 before looping to halve it.
n := shr(1, n)
} n {
// Shift n right by 1 each iteration to halve it.
n := shr(1, n)
} {
// Revert immediately if x ** 2 would overflow.
// Equivalent to iszero(eq(div(xx, x), x)) here.
if shr(128, x) {
revert(0, 0)
}
// Store x squared.
let xx := mul(x, x)
// Round to the nearest number.
let xxRound := add(xx, half)
// Revert if xx + half overflowed.
if lt(xxRound, xx) {
revert(0, 0)
}
// Set x to scaled xxRound.
x := div(xxRound, scalar)
// If n is even:
if mod(n, 2) {
// Compute z * x.
let zx := mul(z, x)
// If z * x overflowed:
if iszero(eq(div(zx, x), z)) {
// Revert if x is non-zero.
if iszero(iszero(x)) {
revert(0, 0)
}
}
// Round to the nearest number.
let zxRound := add(zx, half)
// Revert if zx + half overflowed.
if lt(zxRound, zx) {
revert(0, 0)
}
// Return properly scaled zxRound.
z := div(zxRound, scalar)
}
}
}
}
}
/*//////////////////////////////////////////////////////////////
GENERAL NUMBER UTILITIES
//////////////////////////////////////////////////////////////*/
function sqrt(uint256 x) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
let y := x // We start y at x, which will help us make our initial estimate.
z := 181 // The "correct" value is 1, but this saves a multiplication later.
// This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
// start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.
// We check y >= 2^(k + 8) but shift right by k bits
// each branch to ensure that if x >= 256, then y >= 256.
if iszero(lt(y, 0x10000000000000000000000000000000000)) {
y := shr(128, y)
z := shl(64, z)
}
if iszero(lt(y, 0x1000000000000000000)) {
y := shr(64, y)
z := shl(32, z)
}
if iszero(lt(y, 0x10000000000)) {
y := shr(32, y)
z := shl(16, z)
}
if iszero(lt(y, 0x1000000)) {
y := shr(16, y)
z := shl(8, z)
}
// Goal was to get z*z*y within a small factor of x. More iterations could
// get y in a tighter range. Currently, we will have y in [256, 256*2^16).
// We ensured y >= 256 so that the relative difference between y and y+1 is small.
// That's not possible if x < 256 but we can just verify those cases exhaustively.
// Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
// Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
// Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.
// For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
// (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.
// Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
// sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.
// There is no overflow risk here since y < 2^136 after the first branch above.
z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.
// Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
// If x+1 is a perfect square, the Babylonian method cycles between
// floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
// See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
// Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
// If you don't care whether the floor or ceil square root is returned, you can remove this statement.
z := sub(z, lt(div(x, z), z))
}
}
function unsafeMod(uint256 x, uint256 y) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Mod x by y. Note this will return
// 0 instead of reverting if y is zero.
z := mod(x, y)
}
}
function unsafeDiv(uint256 x, uint256 y) internal pure returns (uint256 r) {
/// @solidity memory-safe-assembly
assembly {
// Divide x by y. Note this will return
// 0 instead of reverting if y is zero.
r := div(x, y)
}
}
function unsafeDivUp(uint256 x, uint256 y) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Add 1 to x * y if x % y > 0. Note this will
// return 0 instead of reverting if y is zero.
z := add(gt(mod(x, y), 0), div(x, y))
}
}
}
"
},
"src/interfaces/IOracle.sol": {
"content": "// SPDX-License-Identifier: MIT
pragma solidity 0.8.28;
interface IOracle {
/// @notice price of a token expressed in a reference token.
/// @dev be mindful of the decimals here, because if quote token
/// doesn't have 18 decimals, value is used to scale the decimals.
/// For example, for USDC quote (6 decimals) expressed in
/// DAI reference (18 decimals), value should be around ~1e30,
/// so that price is:
/// 1e6 * 1e30 / WAD (1e18)
/// ~= WAD (1e18)
/// ~= 1:1
function price() external view returns (uint256);
}
"
},
"lib/openzeppelin-contracts/contracts/token/ERC20/ERC20.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.2.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC-20
* applications.
*/
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
mapping(address account => uint256) private _balances;
mapping(address account => mapping(address spender => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* Both values are immutable: they can only be set once during construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `value`.
*/
function transfer(address to, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_transfer(owner, to, value);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, value);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Skips emitting an {Approval} event indicating an allowance update. This is not
* required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `value`.
* - the caller must have allowance for ``from``'s tokens of at least
* `value`.
*/
function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, value);
_transfer(from, to, value);
return true;
}
/**
* @dev Moves a `value` amount of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _transfer(address from, address to, uint256 value) internal {
if (from == address(0)) {
revert ERC20InvalidSender(address(0));
}
if (to == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(from, to, value);
}
/**
* @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
* (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
* this function.
*
* Emits a {Transfer} event.
*/
function _update(address from, address to, uint256 value) internal virtual {
if (from == address(0)) {
// Overflow check required: The rest of the code assumes that totalSupply never overflows
_totalSupply += value;
} else {
uint256 fromBalance = _balances[from];
if (fromBalance < value) {
revert ERC20InsufficientBalance(from, fromBalance, value);
}
unchecked {
// Overflow not possible: value <= fromBalance <= totalSupply.
_balances[from] = fromBalance - value;
}
}
if (to == address(0)) {
unchecked {
// Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
_totalSupply -= value;
}
} else {
unchecked {
// Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
_balances[to] += value;
}
}
emit Transfer(from, to, value);
}
/**
* @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
* Relies on the `_update` mechanism
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _mint(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(address(0), account, value);
}
/**
* @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
* Relies on the `_update` mechanism.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead
*/
function _burn(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidSender(address(0));
}
_update(account, address(0), value);
}
/**
* @dev Sets `value` as the allowance of `spender` over the `owner`'s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*
* Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
*/
function _approve(address owner, address spender, uint256 value) internal {
_approve(owner, spender, value, true);
}
/**
* @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
*
* By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
* `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
* `Approval` event during `transferFrom` operations.
*
* Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
* true using the following override:
*
* ```solidity
* function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
* super._approve(owner, spender, value, true);
* }
* ```
*
* Requirements are the same as {_approve}.
*/
function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
if (owner == address(0)) {
revert ERC20InvalidApprover(address(0));
}
if (spender == address(0)) {
revert ERC20InvalidSpender(address(0));
}
_allowances[owner][spender] = value;
if (emitEvent) {
emit Approval(owner, spender, value);
}
}
/**
* @dev Updates `owner`'s allowance for `spender` based on spent `value`.
*
* Does not update the allowance value in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Does not emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance < type(uint256).max) {
if (currentAllowance < value) {
revert ERC20InsufficientAllowance(spender, currentAllowance, value);
}
unchecked {
_approve(owner, spender, currentAllowance - value, false);
}
}
}
}
"
},
"lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.2.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
import {IERC1363} from "../../../interfaces/IERC1363.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC-20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
/**
* @dev An operation with an ERC-20 token failed.
*/
error SafeERC20FailedOperation(address token);
/**
* @dev Indicates a failed `decreaseAllowance` request.
*/
error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
}
/**
* @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
*/
function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
}
/**
* @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
*/
function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
return _callOptionalReturnBool(token, abi.encodeCall(token.transferFrom, (from, to, value)));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*
* IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
* smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
* this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
* that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
forceApprove(token, spender, oldAllowance + value);
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
* value, non-reverting calls are assumed to be successful.
*
* IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
* smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
* this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
* that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
*/
function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
unchecked {
uint256 currentAllowance = token.allowance(address(this), spender);
if (currentAllowance < requestedDecrease) {
revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
}
forceApprove(token, spender, currentAllowance - requestedDecrease);
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*
* NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
* only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
* set here.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
* code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
* targeting contracts.
*
* Reverts if the returned value is other than `true`.
*/
function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
if (to.code.length == 0) {
safeTransfer(token, to, value);
} else if (!token.transferAndCall(to, value, data)) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
* has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
* targeting contracts.
*
* Reverts if the returned value is other than `true`.
*/
function transferFromAndCallRelaxed(
IERC1363 token,
address from,
address to,
uint256 value,
bytes memory data
) internal {
if (to.code.length == 0) {
safeTransferFrom(token, from, to, value);
} else if (!token.transferFromAndCall(from, to, value, data)) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
* code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
* targeting contracts.
*
* NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
* Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
* once without retrying, and relies on the returned value to be true.
*
* Reverts if the returned value is other than `true`.
*/
function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
if (to.code.length == 0) {
forceApprove(token, to, value);
} else if (!token.approveAndCall(to, value, data)) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*
* This is a variant of {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
uint256 returnSize;
uint256 returnValue;
assembly ("memory-safe") {
let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
// bubble errors
if iszero(success) {
let ptr := mload(0x40)
returndatacopy(ptr, 0, returndatasize())
revert(ptr, returndatasize())
}
returnSize := returndatasize()
returnValue := mload(0)
}
if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*
* This is a variant of {_callOptionalReturn} that silently catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
bool success;
uint256 returnSize;
uint256 returnValue;
assembly ("memory-safe") {
success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
returnSize := returndatasize()
returnValue := mload(0)
}
return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
}
}
"
},
"lib/openzeppelin-contracts/contracts/interfaces/IERC4626.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/IERC4626.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../token/ERC20/IERC20.sol";
import {IERC20Metadata} from "../token/ERC20/extensions/IERC20Metadata.sol";
/**
* @dev Interface of the ERC-4626 "Tokenized Vault Standard", as defined in
* https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
*/
interface IERC4626 is IERC20, IERC20Metadata {
event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);
event Withdraw(
address indexed sender,
address indexed receiver,
address indexed owner,
uint256 assets,
uint256 shares
);
/**
* @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
*
* - MUST be an ERC-20 token contract.
* - MUST NOT revert.
*/
function asset() external view returns (address assetTokenAddress);
/**
* @dev Returns the total amount of the underlying asset that is “managed” by Vault.
*
* - SHOULD include any compounding that occurs from yield.
* - MUST be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT revert.
*/
function totalAssets() external view returns (uint256 totalManagedAssets);
/**
* @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
* scenario where all the conditions are met.
*
* - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT show any variations depending on the caller.
* - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
* - MUST NOT revert.
*
* NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
* “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
* from.
*/
function convertToShares(uint256 assets) external view returns (uint256 shares);
/**
* @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
* scenario where all the conditions are met.
*
* - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
* - MUST NOT show any variations depending on the caller.
* - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
* - MUST NOT revert.
*
* NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
* “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
* from.
*/
function convertToAssets(uint256 shares) external view returns (uint256 assets);
/**
* @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
* through a deposit call.
*
* - MUST return a limited value if receiver is subject to some deposit limit.
* - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
* - MUST NOT revert.
*/
function maxDeposit(address receiver) external view returns (uint256 maxAssets);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
* current on-chain conditions.
*
* - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
* call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
* in the same transaction.
* - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
* deposit would be accepted, regardless if the user has enough tokens approved, etc.
* - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by depositing.
*/
function previewDeposit(uint256 assets) external view returns (uint256 shares);
/**
* @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
*
* - MUST emit the Deposit event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* deposit execution, and are accounted for during deposit.
* - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
* approving enough underlying tokens to the Vault contract, etc).
*
* NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
*/
function deposit(uint256 assets, address receiver) external returns (uint256 shares);
/**
* @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
* - MUST return a limited value if receiver is subject to some mint limit.
* - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
* - MUST NOT revert.
*/
function maxMint(address receiver) external view returns (uint256 maxShares);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
* current on-chain conditions.
*
* - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
* in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
* same transaction.
* - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
* would be accepted, regardless if the user has enough tokens approved, etc.
* - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by minting.
*/
function previewMint(uint256 shares) external view returns (uint256 assets);
/**
* @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
*
* - MUST emit the Deposit event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
* execution, and are accounted for during mint.
* - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
* approving enough underlying tokens to the Vault contract, etc).
*
* NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
*/
function mint(uint256 shares, address receiver) external returns (uint256 assets);
/**
* @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
* Vault, through a withdraw call.
*
* - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
* - MUST NOT revert.
*/
function maxWithdraw(address owner) external view returns (uint256 maxAssets);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
* given current on-chain conditions.
*
* - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
* call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
* called
* in the same transaction.
* - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
* the withdrawal would be accepted, regardless if the user has enough shares, etc.
* - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by depositing.
*/
function previewWithdraw(uint256 assets) external view returns (uint256 shares);
/**
* @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
*
* - MUST emit the Withdraw event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* withdraw execution, and are accounted for during withdraw.
* - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
* not having enough shares, etc).
*
* Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
* Those methods should be performed separately.
*/
function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);
/**
* @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
* through a redeem call.
*
* - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
* - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
* - MUST NOT revert.
*/
function maxRedeem(address owner) external view returns (uint256 maxShares);
/**
* @dev Allows an on-chain or off-chain user to simulate the effects of their redemption at the current block,
* given current on-chain conditions.
*
* - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
* in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
* same transaction.
* - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
* redemption would be accepted, regardless if the user has enough shares, etc.
* - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
* - MUST NOT revert.
*
* NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
* share price or some other type of condition, meaning the depositor will lose assets by redeeming.
*/
function previewRedeem(uint256 shares) external view returns (uint256 assets);
/**
* @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
*
* - MUST emit the Withdraw event.
* - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
* redeem execution, and are accounted for during redeem.
* - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
* not having enough shares, etc).
*
* NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
* Those methods should be performed separately.
*/
function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
}
"
},
"lib/openzeppelin-contracts/contracts/utils/math/Math.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/math/Math.sol)
pragma solidity ^0.8.20;
import {Panic} from "../Panic.sol";
import {SafeCast} from "./SafeCast.sol";
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Floor, // Toward negative infinity
Ceil, // Toward positive infinity
Trunc, // Toward zero
Expand // Away from zero
}
/**
* @dev Return the 512-bit addition of two uint256.
*
* The result is stored in two 256 variables such that sum = high * 2²⁵⁶ + low.
*/
function add512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
assembly ("memory-safe") {
low := add(a, b)
high := lt(low, a)
}
}
/**
* @dev Return the 512-bit multiplication of two uint256.
*
* The result is stored in two 256 variables such that product = high * 2²⁵⁶ + low.
*/
function mul512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
// 512-bit multiply [high low] = x * y. Compute the product mod 2²⁵⁶ and mod 2²⁵⁶ - 1, then use
// the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = high * 2²⁵⁶ + low.
assembly ("memory-safe") {
let mm := mulmod(a, b, not(0))
low := mul(a, b)
high := sub(sub(mm, low), lt(mm, low))
}
}
/**
* @dev Returns the addition of two unsigned integers, with a success flag (no overflow).
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a + b;
success = c >= a;
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with a success flag (no overflow).
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a - b;
success = c <= a;
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with a success flag (no overflow).
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a * b;
assembly ("memory-safe") {
// Only true when the multiplication doesn't overflow
// (c / a == b) || (a == 0)
success := or(eq(div(c, a), b), iszero(a))
}
// equivalent to: success ? c : 0
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the division of two unsigned integers, with a success flag (no division by zero).
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
success = b > 0;
assembly ("memory-safe") {
// The `DIV` opcode returns zero when the denominator is 0.
result := div(a, b)
}
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a success flag (no division by zero).
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
success = b > 0;
assembly ("memory-safe") {
// The `MOD` opcode returns zero when the denominator is 0.
result := mod(a, b)
}
}
}
/**
* @dev Unsigned saturating addition, bounds to `2²⁵⁶ - 1` instead of overflowing.
*/
function saturatingAdd(uint256 a, uint256 b) internal pure returns (uint256) {
(bool success, uint256 result) = tryAdd(a, b);
return ternary(success, result, type(uint256).max);
}
/**
* @dev Unsigned saturating subtraction, bounds to zero instead of overflowing.
*/
function saturatingSub(uint256 a, uint256 b) internal pure returns (uint256) {
(, uint256 result) = trySub(a, b);
return result;
}
/**
* @dev Unsigned saturating multiplication, bounds to `2²⁵⁶ - 1` instead of overflowing.
*/
function saturatingMul(uint256 a, uint256 b) internal pure returns (uint256) {
(bool success, uint256 result) = tryMul(a, b);
return ternary(success, result, type(uint256).max);
}
/**
* @dev Branchless ternary evaluation for `a ? b : c`. Gas costs are constant.
*
* IMPORTANT: This function may reduce bytecode size and consume less gas when used standalone.
* However, the compiler may optimize Solidity ternary operations (i.e. `a ? b : c`) to only compute
* one branch when needed, making this function more expensive.
*/
function ternary(bool condition, uint256 a, uint256 b) internal pure returns (uint256) {
unchecked {
// branchless ternary works because:
// b ^ (a ^ b) == a
// b ^ 0 == b
return b ^ ((a ^ b) * SafeCast.toUint(condition));
}
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return ternary(a > b, a, b);
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return ternary(a < b, a, b);
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds towards infinity instead
* of
Submitted on: 2025-11-03 18:04:45
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