Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
pragma solidity ^0.8.20;
import {Context} from "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* The initial owner is set to the address provided by the deployer. This can
* later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
/**
* @dev The caller account is not authorized to perform an operation.
*/
error OwnableUnauthorizedAccount(address account);
/**
* @dev The owner is not a valid owner account. (eg. `address(0)`)
*/
error OwnableInvalidOwner(address owner);
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the address provided by the deployer as the initial owner.
*/
constructor(address initialOwner) {
if (initialOwner == address(0)) {
revert OwnableInvalidOwner(address(0));
}
_transferOwnership(initialOwner);
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
if (owner() != _msgSender()) {
revert OwnableUnauthorizedAccount(_msgSender());
}
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
if (newOwner == address(0)) {
revert OwnableInvalidOwner(address(0));
}
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/draft-IERC6093.sol)
pragma solidity ^0.8.20;
/**
* @dev Standard ERC-20 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
*/
interface IERC20Errors {
/**
* @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param balance Current balance for the interacting account.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC20InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC20InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
* @param spender Address that may be allowed to operate on tokens without being their owner.
* @param allowance Amount of tokens a `spender` is allowed to operate with.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC20InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `spender` to be approved. Used in approvals.
* @param spender Address that may be allowed to operate on tokens without being their owner.
*/
error ERC20InvalidSpender(address spender);
}
/**
* @dev Standard ERC-721 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-721 tokens.
*/
interface IERC721Errors {
/**
* @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in ERC-20.
* Used in balance queries.
* @param owner Address of the current owner of a token.
*/
error ERC721InvalidOwner(address owner);
/**
* @dev Indicates a `tokenId` whose `owner` is the zero address.
* @param tokenId Identifier number of a token.
*/
error ERC721NonexistentToken(uint256 tokenId);
/**
* @dev Indicates an error related to the ownership over a particular token. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param tokenId Identifier number of a token.
* @param owner Address of the current owner of a token.
*/
error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC721InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC721InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `operator`’s approval. Used in transfers.
* @param operator Address that may be allowed to operate on tokens without being their owner.
* @param tokenId Identifier number of a token.
*/
error ERC721InsufficientApproval(address operator, uint256 tokenId);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC721InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `operator` to be approved. Used in approvals.
* @param operator Address that may be allowed to operate on tokens without being their owner.
*/
error ERC721InvalidOperator(address operator);
}
/**
* @dev Standard ERC-1155 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-1155 tokens.
*/
interface IERC1155Errors {
/**
* @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param balance Current balance for the interacting account.
* @param needed Minimum amount required to perform a transfer.
* @param tokenId Identifier number of a token.
*/
error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC1155InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC1155InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `operator`’s approval. Used in transfers.
* @param operator Address that may be allowed to operate on tokens without being their owner.
* @param owner Address of the current owner of a token.
*/
error ERC1155MissingApprovalForAll(address operator, address owner);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC1155InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `operator` to be approved. Used in approvals.
* @param operator Address that may be allowed to operate on tokens without being their owner.
*/
error ERC1155InvalidOperator(address operator);
/**
* @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
* Used in batch transfers.
* @param idsLength Length of the array of token identifiers
* @param valuesLength Length of the array of token amounts
*/
error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/IERC1363.sol)
pragma solidity ^0.8.20;
import {IERC20} from "./IERC20.sol";
import {IERC165} from "./IERC165.sol";
/**
* @title IERC1363
* @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
*
* Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
* after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
*/
interface IERC1363 is IERC20, IERC165 {
/*
* Note: the ERC-165 identifier for this interface is 0xb0202a11.
* 0xb0202a11 ===
* bytes4(keccak256('transferAndCall(address,uint256)')) ^
* bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
* bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
* bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
* bytes4(keccak256('approveAndCall(address,uint256)')) ^
* bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
*/
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`
* and then calls {IERC1363Receiver-onTransferReceived} on `to`.
* @param to The address which you want to transfer to.
* @param value The amount of tokens to be transferred.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function transferAndCall(address to, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`
* and then calls {IERC1363Receiver-onTransferReceived} on `to`.
* @param to The address which you want to transfer to.
* @param value The amount of tokens to be transferred.
* @param data Additional data with no specified format, sent in call to `to`.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
* and then calls {IERC1363Receiver-onTransferReceived} on `to`.
* @param from The address which you want to send tokens from.
* @param to The address which you want to transfer to.
* @param value The amount of tokens to be transferred.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function transferFromAndCall(address from, address to, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
* and then calls {IERC1363Receiver-onTransferReceived} on `to`.
* @param from The address which you want to send tokens from.
* @param to The address which you want to transfer to.
* @param value The amount of tokens to be transferred.
* @param data Additional data with no specified format, sent in call to `to`.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function approveAndCall(address spender, uint256 value) external returns (bool);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
* @param data Additional data with no specified format, sent in call to `spender`.
* @return A boolean value indicating whether the operation succeeded unless throwing.
*/
function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC165.sol)
pragma solidity ^0.8.20;
import {IERC165} from "../utils/introspection/IERC165.sol";
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../token/ERC20/IERC20.sol";
// 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}.
*
* All two of these 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);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC-20 standard.
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC-20 standard as defined in the ERC.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the value of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the value of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 value) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the
* allowance mechanism. `value` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
// 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 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);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
pragma solidity ^0.8.20;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
function _contextSuffixLength() internal view virtual returns (uint256) {
return 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/introspection/IERC165.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC-165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[ERC].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// 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 Returns the addition of two unsigned integers, with an success flag (no overflow).
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an success flag (no overflow).
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an success flag (no overflow).
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @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 {
if (b == 0) return (false, 0);
return (true, 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 {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @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 rounding towards zero.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
if (b == 0) {
// Guarantee the same behavior as in a regular Solidity division.
Panic.panic(Panic.DIVISION_BY_ZERO);
}
// The following calculation ensures accurate ceiling division without overflow.
// Since a is non-zero, (a - 1) / b will not overflow.
// The largest possible result occurs when (a - 1) / b is type(uint256).max,
// but the largest value we can obtain is type(uint256).max - 1, which happens
// when a = type(uint256).max and b = 1.
unchecked {
return SafeCast.toUint(a > 0) * ((a - 1) / b + 1);
}
}
/**
* @dev Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
* denominator == 0.
*
* Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
* Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = 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 = prod1 * 2²⁵⁶ + prod0.
uint256 prod0 = x * y; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2²⁵⁶. Also prevents denominator == 0.
if (denominator <= prod1) {
Panic.panic(ternary(denominator == 0, Panic.DIVISION_BY_ZERO, Panic.UNDER_OVERFLOW));
}
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator.
// Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
uint256 twos = denominator & (0 - denominator);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2²⁵⁶ / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2²⁵⁶. Now that denominator is an odd number, it has an inverse modulo 2²⁵⁶ such
// that denominator * inv ≡ 1 mod 2²⁵⁶. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv ≡ 1 mod 2⁴.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
// works in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2⁸
inverse *= 2 - denominator * inverse; // inverse mod 2¹⁶
inverse *= 2 - denominator * inverse; // inverse mod 2³²
inverse *= 2 - denominator * inverse; // inverse mod 2⁶⁴
inverse *= 2 - denominator * inverse; // inverse mod 2¹²⁸
inverse *= 2 - denominator * inverse; // inverse mod 2²⁵⁶
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2²⁵⁶. Since the preconditions guarantee that the outcome is
// less than 2²⁵⁶, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @dev Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
return mulDiv(x, y, denominator) + SafeCast.toUint(unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0);
}
/**
* @dev Calculate the modular multiplicative inverse of a number in Z/nZ.
*
* If n is a prime, then Z/nZ is a field. In that case all elements are inversible, except 0.
* If n is not a prime, then Z/nZ is not a field, and some elements might not be inversible.
*
* If the input value is not inversible, 0 is returned.
*
* NOTE: If you know for sure that n is (big) a prime, it may be cheaper to use Fermat's little theorem and get the
* inverse using `Math.modExp(a, n - 2, n)`. See {invModPrime}.
*/
function invMod(uint256 a, uint256 n) internal pure returns (uint256) {
unchecked {
if (n == 0) return 0;
// The inverse modulo is calculated using the Extended Euclidean Algorithm (iterative version)
// Used to compute integers x and y such that: ax + ny = gcd(a, n).
// When the gcd is 1, then the inverse of a modulo n exists and it's x.
// ax + ny = 1
// ax = 1 + (-y)n
// ax ≡ 1 (mod n) # x is the inverse of a modulo n
// If the remainder is 0 the gcd is n right away.
uint256 remainder = a % n;
uint256 gcd = n;
// Therefore the initial coefficients are:
// ax + ny = gcd(a, n) = n
// 0a + 1n = n
int256 x = 0;
int256 y = 1;
while (remainder != 0) {
uint256 quotient = gcd / remainder;
(gcd, remainder) = (
// The old remainder is the next gcd to try.
remainder,
// Compute the next remainder.
// Can't overflow given that (a % gcd) * (gcd // (a % gcd)) <= gcd
// where gcd is at most n (capped to type(uint256).max)
gcd - remainder * quotient
);
(x, y) = (
// Increment the coefficient of a.
y,
// Decrement the coefficient of n.
// Can overflow, but the result is casted to uint256 so that the
// next value of y is "wrapped around" to a value between 0 and n - 1.
x - y * int256(quotient)
);
}
if (gcd != 1) return 0; // No inverse exists.
return ternary(x < 0, n - uint256(-x), uint256(x)); // Wrap the result if it's negative.
}
}
/**
* @dev Variant of {invMod}. More efficient, but only works if `p` is known to be a prime greater than `2`.
*
* From https://en.wikipedia.org/wiki/Fermat%27s_little_theorem[Fermat's little theorem], we know that if p is
* prime, then `a**(p-1) ≡ 1 mod p`. As a consequence, we have `a * a**(p-2) ≡ 1 mod p`, which means that
* `a**(p-2)` is the modular multiplicative inverse of a in Fp.
*
* NOTE: this function does NOT check that `p` is a prime greater than `2`.
*/
function invModPrime(uint256 a, uint256 p) internal view returns (uint256) {
unchecked {
return Math.modExp(a, p - 2, p);
}
}
/**
* @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m)
*
* Requirements:
* - modulus can't be zero
* - underlying staticcall to precompile must succeed
*
* IMPORTANT: The result is only valid if the underlying call succeeds. When using this function, make
* sure the chain you're using it on supports the precompiled contract for modular exponentiation
* at address 0x05 as specified in https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise,
* the underlying function will succeed given the lack of a revert, but the result may be incorrectly
* interpreted as 0.
*/
function modExp(uint256 b, uint256 e, uint256 m) internal view returns (uint256) {
(bool success, uint256 result) = tryModExp(b, e, m);
if (!success) {
Panic.panic(Panic.DIVISION_BY_ZERO);
}
return result;
}
/**
* @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m).
* It includes a success flag indicating if the operation succeeded. Operation will be marked as failed if trying
* to operate modulo 0 or if the underlying precompile reverted.
*
* IMPORTANT: The result is only valid if the success flag is true. When using this function, make sure the chain
* you're using it on supports the precompiled contract for modular exponentiation at address 0x05 as specified in
* https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise, the underlying function will succeed given the lack
* of a revert, but the result may be incorrectly interpreted as 0.
*/
function tryModExp(uint256 b, uint256 e, uint256 m) internal view returns (bool success, uint256 result) {
if (m == 0) return (false, 0);
assembly ("memory-safe") {
let ptr := mload(0x40)
// | Offset | Content | Content (Hex) |
// |-----------|------------|--------------------------------------------------------------------|
// | 0x00:0x1f | size of b | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x20:0x3f | size of e | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x40:0x5f | size of m | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x60:0x7f | value of b | 0x<.............................................................b> |
// | 0x80:0x9f | value of e | 0x<.............................................................e> |
// | 0xa0:0xbf | value of m | 0x<.............................................................m> |
mstore(ptr, 0x20)
mstore(add(ptr, 0x20), 0x20)
mstore(add(ptr, 0x40), 0x20)
mstore(add(ptr, 0x60), b)
mstore(add(ptr, 0x80), e)
mstore(add(ptr, 0xa0), m)
// Given the result < m, it's guaranteed to fit in 32 bytes,
// so we can use the memory scratch space located at offset 0.
success := staticcall(gas(), 0x05, ptr, 0xc0, 0x00, 0x20)
result := mload(0x00)
}
}
/**
* @dev Variant of {modExp} that supports inputs of arbitrary length.
*/
function modExp(bytes memory b, bytes memory e, bytes memory m) internal view returns (bytes memory) {
(bool success, bytes memory result) = tryModExp(b, e, m);
if (!success) {
Panic.panic(Panic.DIVISION_BY_ZERO);
}
return result;
}
/**
* @dev Variant of {tryModExp} that supports inputs of arbitrary length.
*/
function tryModExp(
bytes memory b,
bytes memory e,
bytes memory m
) internal view returns (bool success, bytes memory result) {
if (_zeroBytes(m)) return (false, new bytes(0));
uint256 mLen = m.length;
// Encode call args in result and move the free memory pointer
result = abi.encodePacked(b.length, e.length, mLen, b, e, m);
assembly ("memory-safe") {
let dataPtr := add(result, 0x20)
// Write result on top of args to avoid allocating extra memory.
success := staticcall(gas(), 0x05, dataPtr, mload(result), dataPtr, mLen)
// Overwrite the length.
// result.length > returndatasize() is guaranteed because returndatasize() == m.length
mstore(result, mLen)
// Set the memory pointer after the returned data.
mstore(0x40, add(dataPtr, mLen))
}
}
/**
* @dev Returns whether the provided byte array is zero.
*/
function _zeroBytes(bytes memory byteArray) private pure returns (bool) {
for (uint256 i = 0; i < byteArray.length; ++i) {
if (byteArray[i] != 0) {
return false;
}
}
return true;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
* towards zero.
*
* This method is based on Newton's method for computing square roots; the algorithm is restricted to only
* using integer operations.
*/
function sqrt(uint256 a) internal pure returns (uint256) {
unchecked {
// Take care of easy edge cases when a == 0 or a == 1
if (a <= 1) {
return a;
}
// In this function, we use Newton's method to get a root of `f(x) := x² - a`. It involves building a
// sequence x_n that converges toward sqrt(a). For each iteration x_n, we also define the error between
// the current value as `ε_n = | x_n - sqrt(a) |`.
//
// For our first estimation, we consider `e` the smallest power of 2 which is bigger than the square root
// of the target. (i.e. `2**(e-1) ≤ sqrt(a) < 2**e`). We know that `e ≤ 128` because `(2¹²⁸)² = 2²⁵⁶` is
// bigger than any uint256.
//
// By noticing that
// `2**(e-1) ≤ sqrt(a) < 2**e → (2**(e-1))² ≤ a < (2**e)² → 2**(2*e-2) ≤ a < 2**(2*e)`
// we can deduce that `e - 1` is `log2(a) / 2`. We can thus compute `x_n = 2**(e-1)` using a method similar
// to the msb function.
uint256 aa = a;
uint256 xn = 1;
if (aa >= (1 << 128)) {
aa >>= 128;
xn <<= 64;
}
if (aa >= (1 << 64)) {
aa >>= 64;
xn <<= 32;
}
if (aa >= (1 << 32)) {
aa >>= 32;
xn <<= 16;
}
if (aa >= (1 << 16)) {
aa >>= 16;
xn <<= 8;
}
if (aa >= (1 << 8)) {
aa >>= 8;
xn <<= 4;
}
if (aa >= (1 << 4)) {
aa >>= 4;
xn <<= 2;
}
if (aa >= (1 << 2)) {
xn <<= 1;
}
// We now have x_n such that `x_n = 2**(e-1) ≤ sqrt(a) < 2**e = 2 * x_n`. This implies ε_n ≤ 2**(e-1).
//
// We can refine our estimation by noticing that the middle of that interval minimizes the error.
// If we move x_n to equal 2**(e-1) + 2**(e-2), then we reduce the error to ε_n ≤ 2**(e-2).
// This is going to be our x_0 (and ε_0)
xn = (3 * xn) >> 1; // ε_0 := | x_0 - sqrt(a) | ≤ 2**(e-2)
// From here, Newton's method give us:
// x_{n+1} = (x_n + a / x_n) / 2
//
// One should note that:
// x_{n+1}² - a = ((x_n + a / x_n) / 2)² - a
// = ((x_n² + a) / (2 * x_n))² - a
// = (x_n⁴ + 2 * a * x_n² + a²) / (4 * x_n²) - a
// = (x_n⁴ + 2 * a * x_n² + a² - 4 * a * x_n²) / (4 * x_n²)
// = (x_n⁴ - 2 * a * x_n² + a²) / (4 * x_n²)
// = (x_n² - a)² / (2 * x_n)²
// = ((x_n² - a) / (2 * x_n))²
// ≥ 0
// Which proves that for all n ≥ 1, sqrt(a) ≤ x_n
//
// This gives us the proof of quadratic convergence of the sequence:
// ε_{n+1} = | x_{n+1} - sqrt(a) |
// = | (x_n + a / x_n) / 2 - sqrt(a) |
// = | (x_n² + a - 2*x_n*sqrt(a)) / (2 * x_n) |
// = | (x_n - sqrt(a))² / (2 * x_n) |
// = | ε_n² / (2 * x_n) |
// = ε_n² / | (2 * x_n) |
//
// For the first iteration, we have a special case where x_0 is known:
// ε_1 = ε_0² / | (2 * x_0) |
// ≤ (2**(e-2))² / (2 * (2**(e-1) + 2**(e-2)))
// ≤ 2**(2*e-4) / (3 * 2**(e-1))
// ≤ 2**(e-3) / 3
// ≤ 2**(e-3-log2(3))
// ≤ 2**(e-4.5)
//
// For the following iterations, we use the fact that, 2**(e-1) ≤ sqrt(a) ≤ x_n:
// ε_{n+1} = ε_n² / | (2 * x_n) |
// ≤ (2**(e-k))² / (2 * 2**(e-1))
// ≤ 2**(2*e-2*k) / 2**e
// ≤ 2**(e-2*k)
xn = (xn + a / xn) >> 1; // ε_1 := | x_1 - sqrt(a) | ≤ 2**(e-4.5) -- special case, see above
xn = (xn + a / xn) >> 1; // ε_2 := | x_2 - sqrt(a) | ≤ 2**(e-9) -- general case with k = 4.5
xn = (xn + a / xn) >> 1; // ε_3 := | x_3 - sqrt(a) | ≤ 2**(e-18) -- general case with k = 9
xn = (xn + a / xn) >> 1; // ε_4 := | x_4 - sqrt(a) | ≤ 2**(e-36) -- general case with k = 18
xn = (xn + a / xn) >> 1; // ε_5 := | x_5 - sqrt(a) | ≤ 2**(e-72) -- general case with k = 36
xn = (xn + a / xn) >> 1; // ε_6 := | x_6 - sqrt(a) | ≤ 2**(e-144) -- general case with k = 72
// Because e ≤ 128 (as discussed during the first estimation phase), we know have reached a precision
// ε_6 ≤ 2**(e-144) < 1. Given we're operating on integers, then we can ensure that xn is now either
// sqrt(a) or sqrt(a) + 1.
return xn - SafeCast.toUint(xn > a / xn);
}
}
/**
* @dev Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && result * result < a);
}
}
/**
* @dev Return the log in base 2 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
uint256 exp;
unchecked {
exp = 128 * SafeCast.toUint(value > (1 << 128) - 1);
value >>= exp;
result += exp;
exp = 64 * SafeCast.toUint(value > (1 << 64) - 1);
value >>= exp;
result += exp;
exp = 32 * SafeCast.toUint(value > (1 << 32) - 1);
value >>= exp;
result += exp;
exp = 16 * SafeCast.toUint(value > (1 << 16) - 1);
value >>= exp;
result += exp;
exp = 8 * SafeCast.toUint(value > (1 << 8) - 1);
value >>= exp;
result += exp;
exp = 4 * SafeCast.toUint(value > (1 << 4) - 1);
value >>= exp;
result += exp;
exp = 2 * SafeCast.toUint(value > (1 << 2) - 1);
value >>= exp;
result += exp;
result += SafeCast.toUint(value > 1);
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << result < value);
}
}
/**
* @dev Return the log in base 10 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 10 ** result < value);
}
}
/**
* @dev Return the log in base 256 of a positive value rounded towards zero.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
uint256 isGt;
unchecked {
isGt = SafeCast.toUint(value > (1 << 128) - 1);
value >>= isGt * 128;
result += isGt * 16;
isGt = SafeCast.toUint(value > (1 << 64) - 1);
value >>= isGt * 64;
result += isGt * 8;
isGt = SafeCast.toUint(value > (1 << 32) - 1);
value >>= isGt * 32;
result += isGt * 4;
isGt = SafeCast.toUint(value > (1 << 16) - 1);
value >>= isGt * 16;
result += isGt * 2;
result += SafeCast.toUint(value > (1 << 8) - 1);
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << (result << 3) < value);
}
}
/**
* @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
*/
function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
return uint8(rounding) % 2 == 1;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/math/SafeCast.sol)
// This file was procedurally generated from scripts/generate/templates/SafeCast.js.
pragma solidity ^0.8.20;
/**
* @dev Wrappers over Solidity's uintXX/intXX/bool casting operators with added overflow
* checks.
*
* Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
* easily result in undesired exploitation or bugs, since developers usually
* assume that overflows raise errors. `SafeCast` restores this intuition by
* reverting the transaction when such an operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeCast {
/**
* @dev Value doesn't fit in an uint of `bits` size.
*/
error SafeCastOverflowedUintDowncast(uint8 bits, uint256 value);
/**
* @dev An int value doesn't fit in an uint of `bits` size.
*/
error SafeCastOverflowedIntToUint(int256 value);
/**
* @dev Value doesn't fit in an int of `bits` size.
*/
error SafeCastOverflowedIntDowncast(uint8 bits, int256 value);
/**
* @dev An uint value doesn't fit in an int of `bits` size.
*/
error SafeCastOverflowedUintToInt(uint256 value);
/**
* @dev Returns the downcasted uint248 from uint256, reverting on
* overflow (when the input is greater than largest uint248).
*
* Counterpart to Solidity's `uint248` operator.
*
* Requirements:
*
* - input must fit into 248 bits
*/
function toUint248(uint256 value) internal pure returns (uint248) {
if (value > type(uint248).max) {
revert SafeCastOverflowedUintDowncast(248, value);
}
return uint248(value);
}
/**
* @dev Returns the downcasted uint240 from uint256, reverting on
* overflow (when the input is greater than largest uint240).
*
* Counterpart to Solidity's `uint240` operator.
*
* Requirements:
*
* - input must fit into 240 bits
*/
function toUint240(uint256 value) internal pure returns (uint240) {
if (value > type(uint240).max) {
revert SafeCastOverflowedUintDowncast(240, value);
}
return uint240(value);
}
/**
* @dev Returns the downcasted uint232 from uint256, reverting on
* overflow (when the input is greater than largest uint232).
*
* Counterpart to Solidity's `uint232` operator.
*
* Requirements:
*
* - input must fit into 232 bits
*/
function toUint232(uint256 value) internal pure returns (uint232) {
if (value > type(uint232).max) {
revert SafeCastOverflowedUintDowncast(232, value);
}
return uint232(value);
}
/**
* @dev Returns the downcasted uint224 from uint256, reverting on
* overflow (when the input is greater than largest uint224).
*
* Counterpart to Solidity's `uint224` operator.
*
* Requirements:
*
* - input must fit into 224 bits
*/
function toUint224(uint256 value) internal pure returns (uint224) {
if (value > type(uint224).max) {
revert SafeCastOverflowedUintDowncast(224, value);
}
return uint224(value);
}
/**
* @dev Returns the downcasted uint216 from uint256, reverting on
* overflow (when the input is greater than largest uint216).
*
* Counterpart to Solidity's `uint216` operator.
*
* Requirements:
*
* - input must fit into 216 bits
*/
function toUint216(uint256 value) internal pure returns (uint216) {
if (value > type(uint216).max) {
revert SafeCastOverflowedUintDowncast(216, value);
}
return uint216(value);
}
/**
* @dev Returns the downcasted uint208 from uint256, reverting on
* overflow (when the input is greater than largest uint208).
*
* Counterpart to Solidity's `uint208` operator.
*
* Requirements:
*
* - input must fit into 208 bits
*/
function toUint208(uint256 value) internal pure returns (uint208) {
if (value > type(uint208).max) {
revert SafeCastOverflowedUintDowncast(208, value);
}
return uint208(value);
}
/**
* @dev Returns the downcasted uint200 from uint256, reverting on
* overflow (when the input is greater than largest uint200).
*
* Counterpart to Solidity's `uint200` operator.
*
* Requirements:
*
* - input must fit into 200 bits
*/
function toUint200(uint256 value) internal pure returns (uint200) {
if (value > type(uint200).max) {
revert SafeCastOverflowedUintDowncast(200, value);
}
return uint200(value);
}
/**
* @dev Returns the downcasted uint192 from uint256, reverting on
* overflow (when the input is greater than largest uint192).
*
* Counterpart to Solidity's `uint192` operator.
*
* Requirements:
*
* - input must fit into 192 bits
*/
function toUint192(uint256 value) internal pure returns (uint192) {
if (value > type(uint192).max) {
revert SafeCastOverflowedUintDowncast(192, value);
}
return uint192(value);
}
/**
* @dev Returns the downcasted uint184 from uint256, reverting on
* overflow (when the input is greater than largest uint184).
*
* Counterpart to Solidity's `uint184` operator.
*
* Requirements:
*
* - input must fit into 184 bits
*/
function toUint184(uint256 value) internal pure returns (uint184) {
if (value > type(uint184).max) {
revert SafeCastOverflowedUintDowncast(184, value);
}
return uint184(value);
}
/**
* @dev Returns the downcasted uint176 from uint256, reverting on
* overflow (when the input is greater than largest uint176).
*
* Counterpart to Solidity's `uint176` operator.
*
* Requirements:
*
* - input must fit into 176 bits
*/
function toUint176(uint256 value) internal pure returns (uint176) {
if (value > type(uint176).max) {
revert SafeCastOverflowedUintDowncast(176, value);
}
return uint176(value);
}
/**
* @dev Returns the downcasted uint168 from uint256, reverting on
* overflow (when the input is greater than largest uint168).
*
* Counterpart to Solidity's `uint168` operator.
*
* Requirements:
*
* - input must fit into 168 bits
*/
function toUint168(uint256 value) internal pure returns (uint168) {
if (value > type(uint168).max) {
revert SafeCastOverflowedUintDowncast(168, value);
}
return uint168(value);
}
/**
* @dev Returns the downcasted uint160 from uint256, reverting on
* overflow (when the input is greater than largest uint160).
*
* Counterpart to Solidity's `uint160` operator.
*
* Requirements:
*
* - input must fit into 160 bits
*/
function toUint160(uint256 value) internal pure returns (uint160) {
if (value > type(uint160).max) {
revert SafeCastOverflowedUintDowncast(160, value);
}
return uint160(value);
}
/**
* @dev Returns the downcasted uint152 from uint256, reverting on
* overflow (when the input is greater than largest uint152).
*
* Counterpart to Solidity's `uint152` operator.
*
* Requirements:
*
* - input must fit into 152 bits
*/
function toUint152(uint256 value) internal pure returns (uint152) {
if (value > type(uint152).max) {
revert SafeCastOverflowedUintDowncast(152, value);
}
return uint152(value);
}
/**
* @dev Returns the downcasted uint144 from uint256, reverting on
* overflow (when the input is greater than largest uint144).
*
* Counterpart to Solidity's `uint144` operator.
*
* Requirements:
*
* - input must fit into 144 bits
*/
function toUint144(uint256 value) internal pure returns (uint144) {
if (value > type(uint144).max) {
revert SafeCastOverflowedUintDowncast(144, value);
}
return uint144(value);
}
/**
* @dev Returns the downcasted uint136 from uint256, reverting on
* overflow (when the input is greater than largest uint136).
*
* Counterpart to Solidity's `uint136` operator.
*
* Requirements:
*
* - input must fit into 136 bits
*/
function toUint136(uint256 value) internal pure returns (uint136) {
if (value > type(uint136).max) {
revert SafeCastOverflowedUintDowncast(136, value);
}
return uint136(value);
}
/**
* @dev Returns the downcasted uint128 from uint256, reverting on
* overflow (when the input is greater than largest uint128).
*
* Counterpart to Solidity's `uint128` operator.
*
* Requirements:
*
* - input must fit into 128 bits
*/
function toUint128(uint256 value) internal pure returns (uint128) {
if (value > type(uint128).max) {
revert SafeCastOverflowedUintDowncast(128, value);
}
return uint128(value);
}
/**
* @dev Returns the downcasted uint120 from uint256, reverting on
* overflow (when the input is greater than largest uint120).
*
* Counterpart to Solidity's `uint120` operator.
*
* Requirements:
*
* - input must fit into 120 bits
*/
function toUint120(uint256 value) internal pure returns (uint120) {
if (value > type(uint120).max) {
revert SafeCastOverflowedUintDowncast(120, value);
}
return uint120(value);
}
/**
* @dev Returns the downcasted uint112 from uint256, reverting on
* overflow (when the input is greater than largest uint112).
*
* Counterpart to Solidity's `uint112` operator.
*
* Requirements:
*
* - input must fit into 112 bits
*/
function toUint112(uint256 value) internal pure returns (uint112) {
if (value > type(uint112).max) {
revert SafeCastOverflowedUintDowncast(112, value);
}
return uint112(value);
}
/**
* @dev Returns the downcasted uint104 from uint256, reverting on
* overflow (when the input is greater than largest uint104).
*
* Counterpart to Solidity's `uint104` operator.
*
* Requirements:
*
* - input must fit into 104 bits
*/
function toUint104(uint256 value) internal pure returns (uint104) {
if (value > type(uint104).max) {
revert SafeCastOverflowedUintDowncast(104, value);
}
return uint104(value);
}
/**
* @dev Returns the downcasted uint96 from uint256, reverting on
* overflow (when the input is greater than largest uint96).
*
* Counterpart to Solidity's `uint96` operator.
*
* Requirements:
*
* - input must fit into 96 bits
*/
function toUint96(uint256 value) internal pure returns (uint96) {
if (value > type(uint96).max) {
revert SafeCastOverflowedUintDowncast(96, value);
}
return uint96(value);
}
/**
* @dev Returns the downcasted uint88 from uint256, reverting on
* overflow (when the input is greater than largest uint88).
*
* Counterpart to Solidity's `uint88` operator.
*
* Requirements:
*
* - input must fit into 88 bits
*/
function toUint88(uint256 value) internal pure returns (uint88) {
if (value > type(uint88).max) {
revert SafeCastOverflowedUintDowncast(88, value);
}
return uint88(value);
}
/**
* @dev Returns the downcasted uint80 from uint256, reverting on
* overflow (when the input is greater than largest uint80).
*
* Counterpart to Solidity's `uint80` operator.
*
* Requirements:
*
* - input must fit into 80 bits
*/
function toUint80(uint256 value) internal pure returns (uint80) {
if (value > type(uint80).max) {
revert SafeCastOverflowedUintDowncast(80, value);
}
return uint80(value);
}
/**
* @dev Returns the downcasted uint72 from uint256, reverting on
* overflow (when the input is greater than largest uint72).
*
* Counterpart to Solidity's `uint72` operator.
*
* Requirements:
*
* - input must fit into 72 bits
*/
function toUint72(uint256 value) internal pure returns (uint72) {
if (value > type(uint72).max) {
revert SafeCastOverflowedUintDowncast(72, value);
}
return uint72(value);
}
/**
* @dev Returns the downcasted uint64 from uint256, reverting on
* overflow (when the input is greater than largest uint64).
*
* Counterpart to Solidity's `uint64` operator.
*
* Requirements:
*
* - input must fit into 64 bits
*/
function toUint64(uint256 value) internal pure returns (uint64) {
if (value > type(uint64).max) {
revert SafeCastOverflowedUintDowncast(64, value);
}
return uint64(value);
}
/**
* @dev Returns the downcasted uint56 from uint256, reverting on
* overflow (when the input is greater than largest uint56).
*
* Counterpart to Solidity's `uint56` operator.
*
* Requirements:
*
* - input must fit into 56 bits
*/
function toUint56(uint256 value) internal pure returns (uint56) {
if (value > type(uint56).max) {
revert SafeCastOverflowedUintDowncast(56, value);
}
return uint56(value);
}
/**
* @dev Returns the downcasted uint48 from uint256, reverting on
* overflow (when the input is greater than largest uint48).
*
* Counterpart to Solidity's `uint48` operator.
*
* Requirements:
*
* - input must fit into 48 bits
*/
function toUint48(uint256 value) internal pure returns (uint48) {
if (value > type(uint48).max) {
revert SafeCastOverflowedUintDowncast(48, value);
}
return uint48(value);
}
/**
* @dev Returns the downcasted uint40 from uint256, reverting on
* overflow (when the input is greater than largest uint40).
*
* Counterpart to Solidity's `uint40` operator.
*
* Requirements:
*
* - input must fit into 40 bits
*/
function toUint40(uint256 value) internal pure returns (uint40) {
if (value > type(uint40).max) {
revert SafeCastOverflowedUintDowncast(40, value);
}
return uint40(value);
}
/**
* @dev Returns the downcasted uint32 from uint256, reverting on
* overflow (when the input is greater than largest uint32).
*
* Counterpart to Solidity's `uint32` operator.
*
* Requirements:
*
* - input must fit into 32 bits
*/
function toUint32(uint256 value) internal pure returns (uint32) {
if (value > type(uint32).max) {
revert SafeCastOverflowedUintDowncast(32, value);
}
return uint32(value);
}
/**
* @dev Returns the downcasted uint24 from uint256, reverting on
* overflow (when the input is greater than largest uint24).
*
* Counterpart to Solidity's `uint24` operator.
*
* Requirements:
*
* - input must fit into 24 bits
*/
function toUint24(uint256 value) internal pure returns (uint24) {
if (value > type(uint24).max) {
revert SafeCastOverflowedUintDowncast(24, value);
}
return uint24(value);
}
/**
* @dev Returns the downcasted uint16 from uint256, reverting on
* overflow (when the input is greater than largest uint16).
*
* Counterpart to Solidity's `uint16` operator.
*
* Requirements:
*
* - input must fit into 16 bits
*/
function toUint16(uint256 value) internal pure returns (uint16) {
if (value > type(uint16).max) {
revert SafeCastOverflowedUintDowncast(16, value);
}
return uint16(value);
}
/**
* @dev Returns the downcasted uint8 from uint256, reverting on
* overflow (when the input is greater than largest uint8).
*
* Counterpart to Solidity's `uint8` operator.
*
* Requirements:
*
* - input must fit into 8 bits
*/
function toUint8(uint256 value) internal pure returns (uint8) {
if (value > type(uint8).max) {
revert SafeCastOverflowedUintDowncast(8, value);
}
return uint8(value);
}
/**
* @dev Converts a signed int256 into an unsigned uint256.
*
* Requirements:
*
* - input must be greater than or equal to 0.
*/
function toUint256(int256 value) internal pure returns (uint256) {
if (value < 0) {
revert SafeCastOverflowedIntToUint(value);
}
return uint256(value);
}
/**
* @dev Returns the downcasted int248 from int256, reverting on
* overflow (when the input is less than smallest int248 or
* greater than largest int248).
*
* Counterpart to Solidity's `int248` operator.
*
* Requirements:
*
* - input must fit into 248 bits
*/
function toInt248(int256 value) internal pure returns (int248 downcasted) {
downcasted = int248(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(248, value);
}
}
/**
* @dev Returns the downcasted int240 from int256, reverting on
* overflow (when the input is less than smallest int240 or
* greater than largest int240).
*
* Counterpart to Solidity's `int240` operator.
*
* Requirements:
*
* - input must fit into 240 bits
*/
function toInt240(int256 value) internal pure returns (int240 downcasted) {
downcasted = int240(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(240, value);
}
}
/**
* @dev Returns the downcasted int232 from int256, reverting on
* overflow (when the input is less than smallest int232 or
* greater than largest int232).
*
* Counterpart to Solidity's `int232` operator.
*
* Requirements:
*
* - input must fit into 232 bits
*/
function toInt232(int256 value) internal pure returns (int232 downcasted) {
downcasted = int232(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(232, value);
}
}
/**
* @dev Returns the downcasted int224 from int256, reverting on
* overflow (when the input is less than smallest int224 or
* greater than largest int224).
*
* Counterpart to Solidity's `int224` operator.
*
* Requirements:
*
* - input must fit into 224 bits
*/
function toInt224(int256 value) internal pure returns (int224 downcasted) {
downcasted = int224(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(224, value);
}
}
/**
* @dev Returns the downcasted int216 from int256, reverting on
* overflow (when the input is less than smallest int216 or
* greater than largest int216).
*
* Counterpart to Solidity's `int216` operator.
*
* Requirements:
*
* - input must fit into 216 bits
*/
function toInt216(int256 value) internal pure returns (int216 downcasted) {
downcasted = int216(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(216, value);
}
}
/**
* @dev Returns the downcasted int208 from int256, reverting on
* overflow (when the input is less than smallest int208 or
* greater than largest int208).
*
* Counterpart to Solidity's `int208` operator.
*
* Requirements:
*
* - input must fit into 208 bits
*/
function toInt208(int256 value) internal pure returns (int208 downcasted) {
downcasted = int208(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(208, value);
}
}
/**
* @dev Returns the downcasted int200 from int256, reverting on
* overflow (when the input is less than smallest int200 or
* greater than largest int200).
*
* Counterpart to Solidity's `int200` operator.
*
* Requirements:
*
* - input must fit into 200 bits
*/
function toInt200(int256 value) internal pure returns (int200 downcasted) {
downcasted = int200(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(200, value);
}
}
/**
* @dev Returns the downcasted int192 from int256, reverting on
* overflow (when the input is less than smallest int192 or
* greater than largest int192).
*
* Counterpart to Solidity's `int192` operator.
*
* Requirements:
*
* - input must fit into 192 bits
*/
function toInt192(int256 value) internal pure returns (int192 downcasted) {
downcasted = int192(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(192, value);
}
}
/**
* @dev Returns the downcasted int184 from int256, reverting on
* overflow (when the input is less than smallest int184 or
* greater than largest int184).
*
* Counterpart to Solidity's `int184` operator.
*
* Requirements:
*
* - input must fit into 184 bits
*/
function toInt184(int256 value) internal pure returns (int184 downcasted) {
downcasted = int184(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(184, value);
}
}
/**
* @dev Returns the downcasted int176 from int256, reverting on
* overflow (when the input is less than smallest int176 or
* greater than largest int176).
*
* Counterpart to Solidity's `int176` operator.
*
* Requirements:
*
* - input must fit into 176 bits
*/
function toInt176(int256 value) internal pure returns (int176 downcasted) {
downcasted = int176(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(176, value);
}
}
/**
* @dev Returns the downcasted int168 from int256, reverting on
* overflow (when the input is less than smallest int168 or
* greater than largest int168).
*
* Counterpart to Solidity's `int168` operator.
*
* Requirements:
*
* - input must fit into 168 bits
*/
function toInt168(int256 value) internal pure returns (int168 downcasted) {
downcasted = int168(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(168, value);
}
}
/**
* @dev Returns the downcasted int160 from int256, reverting on
* overflow (when the input is less than smallest int160 or
* greater than largest int160).
*
* Counterpart to Solidity's `int160` operator.
*
* Requirements:
*
* - input must fit into 160 bits
*/
function toInt160(int256 value) internal pure returns (int160 downcasted) {
downcasted = int160(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(160, value);
}
}
/**
* @dev Returns the downcasted int152 from int256, reverting on
* overflow (when the input is less than smallest int152 or
* greater than largest int152).
*
* Counterpart to Solidity's `int152` operator.
*
* Requirements:
*
* - input must fit into 152 bits
*/
function toInt152(int256 value) internal pure returns (int152 downcasted) {
downcasted = int152(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(152, value);
}
}
/**
* @dev Returns the downcasted int144 from int256, reverting on
* overflow (when the input is less than smallest int144 or
* greater than largest int144).
*
* Counterpart to Solidity's `int144` operator.
*
* Requirements:
*
* - input must fit into 144 bits
*/
function toInt144(int256 value) internal pure returns (int144 downcasted) {
downcasted = int144(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(144, value);
}
}
/**
* @dev Returns the downcasted int136 from int256, reverting on
* overflow (when the input is less than smallest int136 or
* greater than largest int136).
*
* Counterpart to Solidity's `int136` operator.
*
* Requirements:
*
* - input must fit into 136 bits
*/
function toInt136(int256 value) internal pure returns (int136 downcasted) {
downcasted = int136(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(136, value);
}
}
/**
* @dev Returns the downcasted int128 from int256, reverting on
* overflow (when the input is less than smallest int128 or
* greater than largest int128).
*
* Counterpart to Solidity's `int128` operator.
*
* Requirements:
*
* - input must fit into 128 bits
*/
function toInt128(int256 value) internal pure returns (int128 downcasted) {
downcasted = int128(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(128, value);
}
}
/**
* @dev Returns the downcasted int120 from int256, reverting on
* overflow (when the input is less than smallest int120 or
* greater than largest int120).
*
* Counterpart to Solidity's `int120` operator.
*
* Requirements:
*
* - input must fit into 120 bits
*/
function toInt120(int256 value) internal pure returns (int120 downcasted) {
downcasted = int120(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(120, value);
}
}
/**
* @dev Returns the downcasted int112 from int256, reverting on
* overflow (when the input is less than smallest int112 or
* greater than largest int112).
*
* Counterpart to Solidity's `int112` operator.
*
* Requirements:
*
* - input must fit into 112 bits
*/
function toInt112(int256 value) internal pure returns (int112 downcasted) {
downcasted = int112(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(112, value);
}
}
/**
* @dev Returns the downcasted int104 from int256, reverting on
* overflow (when the input is less than smallest int104 or
* greater than largest int104).
*
* Counterpart to Solidity's `int104` operator.
*
* Requirements:
*
* - input must fit into 104 bits
*/
function toInt104(int256 value) internal pure returns (int104 downcasted) {
downcasted = int104(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(104, value);
}
}
/**
* @dev Returns the downcasted int96 from int256, reverting on
* overflow (when the input is less than smallest int96 or
* greater than largest int96).
*
* Counterpart to Solidity's `int96` operator.
*
* Requirements:
*
* - input must fit into 96 bits
*/
function toInt96(int256 value) internal pure returns (int96 downcasted) {
downcasted = int96(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(96, value);
}
}
/**
* @dev Returns the downcasted int88 from int256, reverting on
* overflow (when the input is less than smallest int88 or
* greater than largest int88).
*
* Counterpart to Solidity's `int88` operator.
*
* Requirements:
*
* - input must fit into 88 bits
*/
function toInt88(int256 value) internal pure returns (int88 downcasted) {
downcasted = int88(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(88, value);
}
}
/**
* @dev Returns the downcasted int80 from int256, reverting on
* overflow (when the input is less than smallest int80 or
* greater than largest int80).
*
* Counterpart to Solidity's `int80` operator.
*
* Requirements:
*
* - input must fit into 80 bits
*/
function toInt80(int256 value) internal pure returns (int80 downcasted) {
downcasted = int80(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(80, value);
}
}
/**
* @dev Returns the downcasted int72 from int256, reverting on
* overflow (when the input is less than smallest int72 or
* greater than largest int72).
*
* Counterpart to Solidity's `int72` operator.
*
* Requirements:
*
* - input must fit into 72 bits
*/
function toInt72(int256 value) internal pure returns (int72 downcasted) {
downcasted = int72(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(72, value);
}
}
/**
* @dev Returns the downcasted int64 from int256, reverting on
* overflow (when the input is less than smallest int64 or
* greater than largest int64).
*
* Counterpart to Solidity's `int64` operator.
*
* Requirements:
*
* - input must fit into 64 bits
*/
function toInt64(int256 value) internal pure returns (int64 downcasted) {
downcasted = int64(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(64, value);
}
}
/**
* @dev Returns the downcasted int56 from int256, reverting on
* overflow (when the input is less than smallest int56 or
* greater than largest int56).
*
* Counterpart to Solidity's `int56` operator.
*
* Requirements:
*
* - input must fit into 56 bits
*/
function toInt56(int256 value) internal pure returns (int56 downcasted) {
downcasted = int56(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(56, value);
}
}
/**
* @dev Returns the downcasted int48 from int256, reverting on
* overflow (when the input is less than smallest int48 or
* greater than largest int48).
*
* Counterpart to Solidity's `int48` operator.
*
* Requirements:
*
* - input must fit into 48 bits
*/
function toInt48(int256 value) internal pure returns (int48 downcasted) {
downcasted = int48(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(48, value);
}
}
/**
* @dev Returns the downcasted int40 from int256, reverting on
* overflow (when the input is less than smallest int40 or
* greater than largest int40).
*
* Counterpart to Solidity's `int40` operator.
*
* Requirements:
*
* - input must fit into 40 bits
*/
function toInt40(int256 value) internal pure returns (int40 downcasted) {
downcasted = int40(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(40, value);
}
}
/**
* @dev Returns the downcasted int32 from int256, reverting on
* overflow (when the input is less than smallest int32 or
* greater than largest int32).
*
* Counterpart to Solidity's `int32` operator.
*
* Requirements:
*
* - input must fit into 32 bits
*/
function toInt32(int256 value) internal pure returns (int32 downcasted) {
downcasted = int32(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(32, value);
}
}
/**
* @dev Returns the downcasted int24 from int256, reverting on
* overflow (when the input is less than smallest int24 or
* greater than largest int24).
*
* Counterpart to Solidity's `int24` operator.
*
* Requirements:
*
* - input must fit into 24 bits
*/
function toInt24(int256 value) internal pure returns (int24 downcasted) {
downcasted = int24(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(24, value);
}
}
/**
* @dev Returns the downcasted int16 from int256, reverting on
* overflow (when the input is less than smallest int16 or
* greater than largest int16).
*
* Counterpart to Solidity's `int16` operator.
*
* Requirements:
*
* - input must fit into 16 bits
*/
function toInt16(int256 value) internal pure returns (int16 downcasted) {
downcasted = int16(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(16, value);
}
}
/**
* @dev Returns the downcasted int8 from int256, reverting on
* overflow (when the input is less than smallest int8 or
* greater than largest int8).
*
* Counterpart to Solidity's `int8` operator.
*
* Requirements:
*
* - input must fit into 8 bits
*/
function toInt8(int256 value) internal pure returns (int8 downcasted) {
downcasted = int8(value);
if (downcasted != value) {
revert SafeCastOverflowedIntDowncast(8, value);
}
}
/**
* @dev Converts an unsigned uint256 into a signed int256.
*
* Requirements:
*
* - input must be less than or equal to maxInt256.
*/
function toInt256(uint256 value) internal pure returns (int256) {
// Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
if (value > uint256(type(int256).max)) {
revert SafeCastOverflowedUintToInt(value);
}
return int256(value);
}
/**
* @dev Cast a boolean (false or true) to a uint256 (0 or 1) with no jump.
*/
function toUint(bool b) internal pure returns (uint256 u) {
assembly ("memory-safe") {
u := iszero(iszero(b))
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/Panic.sol)
pragma solidity ^0.8.20;
/**
* @dev Helper library for emitting standardized panic codes.
*
* ```solidity
* contract Example {
* using Panic for uint256;
*
* // Use any of the declared internal constants
* function foo() { Panic.GENERIC.panic(); }
*
* // Alternatively
* function foo() { Panic.panic(Panic.GENERIC); }
* }
* ```
*
* Follows the list from https://github.com/ethereum/solidity/blob/v0.8.24/libsolutil/ErrorCodes.h[libsolutil].
*
* _Available since v5.1._
*/
// slither-disable-next-line unused-state
library Panic {
/// @dev generic / unspecified error
uint256 internal constant GENERIC = 0x00;
/// @dev used by the assert() builtin
uint256 internal constant ASSERT = 0x01;
/// @dev arithmetic underflow or overflow
uint256 internal constant UNDER_OVERFLOW = 0x11;
/// @dev division or modulo by zero
uint256 internal constant DIVISION_BY_ZERO = 0x12;
/// @dev enum conversion error
uint256 internal constant ENUM_CONVERSION_ERROR = 0x21;
/// @dev invalid encoding in storage
uint256 internal constant STORAGE_ENCODING_ERROR = 0x22;
/// @dev empty array pop
uint256 internal constant EMPTY_ARRAY_POP = 0x31;
/// @dev array out of bounds access
uint256 internal constant ARRAY_OUT_OF_BOUNDS = 0x32;
/// @dev resource error (too large allocation or too large array)
uint256 internal constant RESOURCE_ERROR = 0x41;
/// @dev calling invalid internal function
uint256 internal constant INVALID_INTERNAL_FUNCTION = 0x51;
/// @dev Reverts with a panic code. Recommended to use with
/// the internal constants with predefined codes.
function panic(uint256 code) internal pure {
assembly ("memory-safe") {
mstore(0x00, 0x4e487b71)
mstore(0x20, code)
revert(0x1c, 0x24)
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/ReentrancyGuard.sol)
pragma solidity ^0.8.20;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If EIP-1153 (transient storage) is available on the chain you're deploying at,
* consider using {ReentrancyGuardTransient} instead.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant NOT_ENTERED = 1;
uint256 private constant ENTERED = 2;
uint256 private _status;
/**
* @dev Unauthorized reentrant call.
*/
error ReentrancyGuardReentrantCall();
constructor() {
_status = NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
// On the first call to nonReentrant, _status will be NOT_ENTERED
if (_status == ENTERED) {
revert ReentrancyGuardReentrantCall();
}
// Any calls to nonReentrant after this point will fail
_status = ENTERED;
}
function _nonReentrantAfter() private {
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/
function _reentrancyGuardEntered() internal view returns (bool) {
return _status == ENTERED;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";
/**
* @title BondingCurve
* @dev Implementation of Bancor Formula bonding curve for token pricing and liquidity
*/
contract BondingCurve is Ownable, ReentrancyGuard {
using SafeERC20 for IERC20;
// State variables
IERC20 public token; // Token being traded
uint256 public constant PRECISION = 1e18; // Standard precision
uint256 public constant MAX_RESERVE_RATIO = 1000000; // 100% in ppm
uint256 public constant FUNDING_GOAL = 400000 ether; // 400,000 ETH funding goal
uint256 public constant INITIAL_PRICE = 0.0001 ether; // Initial price: 0.0001 ETH per token
uint256 public constant INITIAL_SUPPLY = 1_000_000_000 * 1e18; // 1 billion tokens
uint256 public constant INITIAL_RESERVE = 100000 ether; // Initial reserve of 100,000 ETH
uint256 public reserveWeight; // Reserve weight in ppm (1-1000000)
uint256 public initialSupply; // Initial token supply (S₀)
uint256 public totalSupply; // Current supply in the bonding curve
uint256 public fundingRaised; // Total funding raised in ETH
uint256 public reserveBalance; // Current ETH reserve balance
bool public fundingGoalReached; // Flag to track if funding goal is reached
uint256 public fundingEndTime; // Timestamp when funding goal was reached
// Add new constants for S-curve parameters
uint256 public constant CURVE_STEEPNESS = 2e18; // m determines how aggressively the curve accelerates
uint256 public constant CURVE_SHIFT = 100000 * 1e18; // b determines the inflection point
uint256 public constant MAX_PRICE = 5 ether; // Maximum price cap
uint256 public constant MIN_TOKEN_AMOUNT = 1e15; // Minimum token amount (0.001)
// Price tracking
uint256 private lastPrice;
// Events
event Buy(address indexed buyer, uint256 tokenAmount, uint256 paymentAmount);
event Sell(address indexed seller, uint256 tokenAmount, uint256 paymentAmount);
event FundingRaised(uint256 amount);
event FundingGoalReached(uint256 timestamp);
constructor(
address _token,
uint256 _reserveWeight,
uint256 _initialSupply
) Ownable(msg.sender) {
require(_token != address(0), "Invalid token address");
require(_reserveWeight > 0 && _reserveWeight <= MAX_RESERVE_RATIO, "Invalid reserve weight");
require(_initialSupply > 0, "Initial supply must be positive");
token = IERC20(_token);
reserveWeight = _reserveWeight;
initialSupply = _initialSupply;
totalSupply = 0;
fundingRaised = 0;
reserveBalance = INITIAL_RESERVE;
}
/**
* @dev Power function for calculating token price
* @param base Base number
* @param exp Exponent in PRECISION
* @return result Result of base^exp
*/
function pow(uint256 base, uint256 exp) internal pure returns (uint256) {
require(base > 0, "Base must be positive");
if (base == PRECISION) {
return PRECISION;
}
if (exp == 0) {
return PRECISION;
}
if (exp == PRECISION) {
return base;
}
// Use logarithmic properties for the calculation
uint256 logBase = _ln(base);
uint256 logResult = (logBase * exp) / PRECISION;
return _exp(logResult);
}
/**
* @dev Natural logarithm function
* @param x Value to calculate ln(x)
* @return Natural logarithm result
*/
function _ln(uint256 x) internal pure returns (uint256) {
require(x > 0, "Cannot calculate ln of 0");
uint256 result = 0;
uint256 y = x;
while (y < PRECISION) {
y = (y * 10) / 1;
result -= PRECISION / 10;
}
y = y / 10;
for (uint8 i = 0; i < 10; i++) {
y = (y * y) / PRECISION;
if (y >= 10 * PRECISION) {
result += PRECISION;
y = y / 10;
}
}
return result;
}
/**
* @dev Exponential function
* @param x Value to calculate e^x
* @return Exponential result
*/
function _exp(uint256 x) internal pure returns (uint256) {
require(x <= 2 ** 255 - 1, "Overflow");
uint256 result = PRECISION;
uint256 xi = x;
uint256 term = PRECISION;
for (uint8 i = 1; i <= 8; i++) {
term = (term * xi) / (i * PRECISION);
result += term;
}
return result;
}
/**
* @dev Calculate S-curve value: y = 1 / (1 + e^(-m(x+b)))
* Using the sigmoid function as recommended by Coinweb
*/
function calculateSCurve(uint256 x) internal pure returns (uint256) {
// Scale down input to avoid overflow
uint256 scaled_x = x / 1e9;
uint256 scaled_shift = CURVE_SHIFT / 1e9;
// Calculate -m(x+b) with proper scaling
int256 mx = -int256((CURVE_STEEPNESS * (scaled_x + scaled_shift)) / PRECISION);
// Calculate e^(-m(x+b))
uint256 expValue = _expSigned(mx);
// Calculate final S-curve value
return (PRECISION * PRECISION) / (PRECISION + expValue);
}
/**
* @dev Exponential function that handles negative exponents
* @param x Value to calculate e^x
* @return Exponential result scaled to PRECISION
*/
function _expSigned(int256 x) internal pure returns (uint256) {
if (x > 0) {
return _exp(uint256(x));
} else {
return PRECISION * PRECISION / _exp(uint256(-x));
}
}
/**
* @dev Get current token price using S-curve
* Price increases more aggressively during growth phase and decelerates at maturity
*/
function getCurrentPrice() public returns (uint256) {
if (totalSupply == 0) {
lastPrice = INITIAL_PRICE;
return INITIAL_PRICE;
}
// Calculate progress along S-curve (0 to 1)
uint256 curveValue = calculateSCurve(totalSupply);
// Scale the price between INITIAL_PRICE and MAX_PRICE
uint256 priceRange = MAX_PRICE - INITIAL_PRICE;
uint256 priceDelta = (priceRange * curveValue) / PRECISION;
// Calculate new price
uint256 newPrice = INITIAL_PRICE + priceDelta;
// Price can only increase
if (newPrice > lastPrice) {
lastPrice = newPrice;
}
return lastPrice;
}
// Add a view version of getCurrentPrice that doesn't update lastPrice
function getCurrentPriceView() public view returns (uint256) {
if (totalSupply == 0) {
return INITIAL_PRICE;
}
uint256 curveValue = calculateSCurve(totalSupply);
uint256 priceRange = MAX_PRICE - INITIAL_PRICE;
uint256 priceDelta = (priceRange * curveValue) / PRECISION;
uint256 newPrice = INITIAL_PRICE + priceDelta;
return newPrice > lastPrice ? newPrice : lastPrice;
}
/**
* @dev Calculate tokens to receive for ETH amount
* Allows fractional token purchases
*/
function calculateTokensForEth(uint256 ethAmount) public returns (uint256) {
require(ethAmount > 0, "ETH amount must be positive");
// For initial purchase
if (totalSupply == 0) {
return (ethAmount * PRECISION) / INITIAL_PRICE;
}
// Get current price per token
uint256 currentPrice = getCurrentPrice();
require(currentPrice > 0, "Invalid token price");
// Calculate tokens to receive
uint256 tokensToReceive = (ethAmount * PRECISION) / currentPrice;
require(tokensToReceive >= MIN_TOKEN_AMOUNT, "Amount too small");
// Check available supply
uint256 availableSupply = initialSupply - totalSupply;
if (tokensToReceive > availableSupply) {
tokensToReceive = availableSupply;
}
return tokensToReceive;
}
/**
* @dev Calculate ETH to receive for token amount
* Uses average price between pre-sell and post-sell to reduce price impact
*/
function calculateEthForTokens(uint256 tokenAmount) public returns (uint256) {
require(tokenAmount > 0, "Token amount must be positive");
require(tokenAmount <= totalSupply, "Insufficient supply");
// Get price before selling
uint256 preSellPrice = getCurrentPrice();
// Simulate price after selling
uint256 newSupply = totalSupply - tokenAmount;
uint256 postSellPrice = preSellPrice;
if (newSupply > 0) {
// Calculate new price using S-curve
uint256 curveValue = calculateSCurve(newSupply);
uint256 priceRange = MAX_PRICE - INITIAL_PRICE;
uint256 priceDelta = (priceRange * curveValue) / PRECISION;
postSellPrice = INITIAL_PRICE + priceDelta;
}
// Use average price to reduce impact
uint256 avgPrice = (preSellPrice + postSellPrice) / 2;
require(avgPrice > 0, "Invalid average price");
return (tokenAmount * avgPrice) / PRECISION;
}
/**
* @dev Buy tokens using ETH
* @param minTokens Minimum amount of tokens to receive
* @param buyer Address of the token buyer
*/
function buy(uint256 minTokens, address buyer) external payable nonReentrant {
require(!fundingGoalReached, "Funding goal already reached");
require(fundingRaised < FUNDING_GOAL, "Funding goal exceeded");
require(msg.value > 0, "Must send ETH");
require(buyer != address(0), "Invalid buyer address");
uint256 currentPrice = getCurrentPrice();
uint256 tokensToReceive = calculateTokensForEth(msg.value);
require(tokensToReceive > 0,
string(abi.encodePacked(
"Will receive ",
toString(tokensToReceive / PRECISION),
" tokens at current price of ",
toString(currentPrice / PRECISION),
" ETH per token"
))
);
require(tokensToReceive >= minTokens, "Slippage too high");
// Check contract balance
uint256 contractBalance = token.balanceOf(address(this));
require(contractBalance >= tokensToReceive, "Insufficient token balance");
// Check if this purchase would exceed funding goal
require(fundingRaised + msg.value <= FUNDING_GOAL, "Purchase would exceed funding goal");
// Update state before transfer
totalSupply += tokensToReceive;
fundingRaised += msg.value;
reserveBalance += msg.value;
// Transfer tokens to buyer
token.safeTransfer(buyer, tokensToReceive);
// Check if funding goal is reached
if (fundingRaised >= FUNDING_GOAL && !fundingGoalReached) {
fundingGoalReached = true;
fundingEndTime = block.timestamp;
emit FundingGoalReached(block.timestamp);
}
emit Buy(buyer, tokensToReceive, msg.value);
emit FundingRaised(msg.value);
}
/**
* @dev Sell tokens back to the contract
* @param tokenAmount Amount of tokens to sell
* @param minEth Minimum ETH to receive
*/
function sell(uint256 tokenAmount, uint256 minEth) external nonReentrant {
require(tokenAmount > 0, "Amount must be positive");
require(totalSupply >= tokenAmount, "Cannot sell more than supply");
uint256 ethToReceive = calculateEthForTokens(tokenAmount);
require(ethToReceive >= minEth, "Below min return");
require(reserveBalance >= ethToReceive, "Insufficient reserve");
// Transfer tokens from seller
token.safeTransferFrom(msg.sender, address(this), tokenAmount);
// Update state - note that we don't reduce fundingRaised
totalSupply -= tokenAmount;
reserveBalance -= ethToReceive;
// Transfer ETH to seller
(bool success, ) = msg.sender.call{value: ethToReceive}("");
require(success, "ETH transfer failed");
emit Sell(msg.sender, tokenAmount, ethToReceive);
}
/**
* @dev Get total market capitalization in ETH
* @return Total market cap in wei
*/
function getTotalMarketCap() external view returns (uint256) {
if (totalSupply == 0) return 0;
return getCurrentPriceView() * totalSupply / PRECISION;
}
/**
* @dev Get total funding raised
* @return Total funding in wei
*/
function getTotalFundingRaised() external view returns (uint256) {
return fundingRaised;
}
/**
* @dev Get holder's token percentage compared to initial supply
* @param holder Address of the holder
* @return percentage Percentage with 2 decimals (e.g., 534 = 5.34%)
*/
function getHolderTokenPercentage(address holder) external view returns (uint256) {
require(holder != address(0), "Invalid address");
uint256 holderBalance = token.balanceOf(holder);
if (holderBalance == 0) return 0;
// Return percentage with 2 decimals
return (holderBalance * 10000) / initialSupply;
}
/**
* @dev Get top holder percentages
* @param holders Array of holder addresses to check
* @return percentages Array of percentages with 2 decimals
*/
function getMultipleHolderPercentages(address[] calldata holders) external view returns (uint256[] memory) {
uint256[] memory percentages = new uint256[](holders.length);
for(uint256 i = 0; i < holders.length; i++) {
if(holders[i] == address(0)) {
percentages[i] = 0;
continue;
}
uint256 holderBalance = token.balanceOf(holders[i]);
percentages[i] = holderBalance > 0 ? (holderBalance * 10000) / initialSupply : 0;
}
return percentages;
}
/**
* @dev Get funding progress percentage
* @return progress Percentage with 2 decimals (e.g., 8350 = 83.50%)
*/
function getFundingProgress() external view returns (uint256) {
if (fundingRaised == 0) return 0;
return (fundingRaised * 10000) / FUNDING_GOAL;
}
/**
* @dev Get remaining funding amount needed
* @return remaining Amount in ETH needed to reach goal
*/
function getRemainingFunding() external view returns (uint256) {
if (fundingGoalReached || fundingRaised >= FUNDING_GOAL) {
return 0;
}
return FUNDING_GOAL - fundingRaised;
}
/**
* @dev Get funding duration if goal reached
* @return duration Time in seconds from contract creation to goal reached
*/
function getFundingDuration() external view returns (uint256) {
if (!fundingGoalReached) {
return 0;
}
return fundingEndTime;
}
/**
* @dev Check if funding is active
* @return bool True if funding is still active
*/
function isFundingActive() public view returns (bool) {
return !fundingGoalReached && fundingRaised < FUNDING_GOAL;
}
// Helper function to convert uint to string
function toString(uint256 value) internal pure returns (string memory) {
if (value == 0) return "0";
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
// Function to receive ETH
receive() external payable {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract ContractErc20 is ERC20, Ownable {
constructor(
string memory name,
string memory symbol,
uint256 initialSupply
) ERC20(name, symbol) Ownable(msg.sender) {
_mint(msg.sender, initialSupply);
}
function mint(address to, uint256 amount) external onlyOwner {
_mint(to, amount);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "./BondingCurve.sol";
import "./ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
/**
* @title Factory
* @dev Factory contract for creating Continuous Token and Bonding Curve pairs
* Implements Continuous Organization model with Automated Market Maker
*/
contract Factory is Ownable {
// Constants
uint256 public constant DEFAULT_RESERVE_WEIGHT = 500000; // 50% in ppm
uint256 public constant FIXED_INITIAL_SUPPLY = 1_000_000_000 * 10**18; // 1 billion tokens
uint256 public constant CURVE_ALLOCATION = 800000; // 80% for bonding curve
uint256 public constant CREATOR_ALLOCATION = 200000; // 20% for creator
uint256 public constant CREATION_FEE = 1 ether; // Fixed creation fee
// Mappings for token tracking
mapping(address => address) public tokenToCurve;
mapping(address => address) public curveToToken;
mapping(address => bool) public isTokenRegistered;
// Arrays to store all created tokens and curves
address[] public allTokens;
address[] public allCurves;
// Events
event TokenAndCurveCreated(
address indexed token,
address indexed bondingCurve,
string name,
string symbol,
uint256 initialSupply,
uint256 timestamp
);
constructor() Ownable(msg.sender) {}
/**
* @dev Create new Continuous Token and its Bonding Curve
* @param name Token name
* @param symbol Token symbol
*/
function createTokenAndCurve(
string memory name,
string memory symbol
) external payable {
require(msg.value >= CREATION_FEE, "Insufficient creation fee");
// Calculate allocations
uint256 bondingCurveAllocation = (FIXED_INITIAL_SUPPLY * CURVE_ALLOCATION) / 1000000;
uint256 creatorAllocation = (FIXED_INITIAL_SUPPLY * CREATOR_ALLOCATION) / 1000000;
// Deploy Continuous Token
ContractErc20 newToken = new ContractErc20(
name,
symbol,
FIXED_INITIAL_SUPPLY
);
// Deploy Bonding Curve (Automated Market Maker)
BondingCurve newCurve = new BondingCurve(
address(newToken),
DEFAULT_RESERVE_WEIGHT,
bondingCurveAllocation
);
// Setup initial allocations
newToken.approve(address(newCurve), bondingCurveAllocation);
// Transfer 80% to bonding curve
newToken.transfer(address(newCurve), bondingCurveAllocation);
// Transfer 20% to creator
newToken.transfer(msg.sender, creatorAllocation);
// Register token-curve pair
tokenToCurve[address(newToken)] = address(newCurve);
curveToToken[address(newCurve)] = address(newToken);
isTokenRegistered[address(newToken)] = true;
// Add to tracking arrays
allTokens.push(address(newToken));
allCurves.push(address(newCurve));
// Transfer ownership
newToken.transferOwnership(msg.sender);
newCurve.transferOwnership(msg.sender);
emit TokenAndCurveCreated(
address(newToken),
address(newCurve),
name,
symbol,
FIXED_INITIAL_SUPPLY,
block.timestamp
);
// Refund excess ETH
uint256 excess = msg.value - CREATION_FEE;
if (excess > 0) {
(bool success, ) = msg.sender.call{value: excess}("");
require(success, "ETH refund failed");
}
}
/**
* @dev Get total number of tokens created
*/
function getTotalTokens() external view returns (uint256) {
return allTokens.length;
}
/**
* @dev Get latest created token and curve
*/
function getLatestToken() external view returns (address token, address curve) {
require(allTokens.length > 0, "No tokens created");
token = allTokens[allTokens.length - 1];
curve = allCurves[allCurves.length - 1];
}
/**
* @dev Withdraw collected fees
*/
function withdrawFees() external onlyOwner {
uint256 balance = address(this).balance;
require(balance > 0, "No fees to withdraw");
(bool success, ) = msg.sender.call{value: balance}("");
require(success, "Fee withdrawal failed");
}
// Function to receive ETH
receive() external payable {}
}