Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import "@thesis/solidity-contracts/contracts/token/ERC20WithPermit.sol";
import "@thesis/solidity-contracts/contracts/token/MisfundRecovery.sol";
contract TBTC is ERC20WithPermit, MisfundRecovery {
constructor() ERC20WithPermit("tBTC v2", "tBTC") {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts/access/Ownable.sol";
import "./IERC20WithPermit.sol";
import "./IReceiveApproval.sol";
/// @title ERC20WithPermit
/// @notice Burnable ERC20 token with EIP2612 permit functionality. User can
/// authorize a transfer of their token with a signature conforming
/// EIP712 standard instead of an on-chain transaction from their
/// address. Anyone can submit this signature on the user's behalf by
/// calling the permit function, as specified in EIP2612 standard,
/// paying gas fees, and possibly performing other actions in the same
/// transaction.
contract ERC20WithPermit is IERC20WithPermit, Ownable {
/// @notice The amount of tokens owned by the given account.
mapping(address => uint256) public override balanceOf;
/// @notice The remaining number of tokens that spender will be
/// allowed to spend on behalf of owner through `transferFrom` and
/// `burnFrom`. This is zero by default.
mapping(address => mapping(address => uint256)) public override allowance;
/// @notice Returns the current nonce for EIP2612 permission for the
/// provided token owner for a replay protection. Used to construct
/// EIP2612 signature provided to `permit` function.
mapping(address => uint256) public override nonces;
uint256 public immutable cachedChainId;
bytes32 public immutable cachedDomainSeparator;
/// @notice Returns EIP2612 Permit message hash. Used to construct EIP2612
/// signature provided to `permit` function.
bytes32 public constant override PERMIT_TYPEHASH =
keccak256(
"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
);
/// @notice The amount of tokens in existence.
uint256 public override totalSupply;
/// @notice The name of the token.
string public override name;
/// @notice The symbol of the token.
string public override symbol;
/// @notice The decimals places of the token.
uint8 public constant override decimals = 18;
constructor(string memory _name, string memory _symbol) {
name = _name;
symbol = _symbol;
cachedChainId = block.chainid;
cachedDomainSeparator = buildDomainSeparator();
}
/// @notice Moves `amount` tokens from the caller's account to `recipient`.
/// @return True if the operation succeeded, reverts otherwise.
/// @dev Requirements:
/// - `recipient` cannot be the zero address,
/// - the caller must have a balance of at least `amount`.
function transfer(address recipient, uint256 amount)
external
override
returns (bool)
{
_transfer(msg.sender, recipient, amount);
return true;
}
/// @notice Moves `amount` tokens from `sender` to `recipient` using the
/// allowance mechanism. `amount` is then deducted from the caller's
/// allowance unless the allowance was made for `type(uint256).max`.
/// @return True if the operation succeeded, reverts otherwise.
/// @dev Requirements:
/// - `sender` and `recipient` cannot be the zero address,
/// - `sender` must have a balance of at least `amount`,
/// - the caller must have allowance for `sender`'s tokens of at least
/// `amount`.
function transferFrom(
address sender,
address recipient,
uint256 amount
) external override returns (bool) {
uint256 currentAllowance = allowance[sender][msg.sender];
if (currentAllowance != type(uint256).max) {
require(
currentAllowance >= amount,
"Transfer amount exceeds allowance"
);
_approve(sender, msg.sender, currentAllowance - amount);
}
_transfer(sender, recipient, amount);
return true;
}
/// @notice EIP2612 approval made with secp256k1 signature.
/// Users can authorize a transfer of their tokens with a signature
/// conforming EIP712 standard, rather than an on-chain transaction
/// from their address. Anyone can submit this signature on the
/// user's behalf by calling the permit function, paying gas fees,
/// and possibly performing other actions in the same transaction.
/// @dev The deadline argument can be set to `type(uint256).max to create
/// permits that effectively never expire. If the `amount` is set
/// to `type(uint256).max` then `transferFrom` and `burnFrom` will
/// not reduce an allowance.
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external override {
/* solhint-disable-next-line not-rely-on-time */
require(deadline >= block.timestamp, "Permission expired");
// Validate `s` and `v` values for a malleability concern described in EIP2.
// Only signatures with `s` value in the lower half of the secp256k1
// curve's order and `v` value of 27 or 28 are considered valid.
require(
uint256(s) <=
0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0,
"Invalid signature 's' value"
);
require(v == 27 || v == 28, "Invalid signature 'v' value");
bytes32 digest = keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR(),
keccak256(
abi.encode(
PERMIT_TYPEHASH,
owner,
spender,
amount,
nonces[owner]++,
deadline
)
)
)
);
address recoveredAddress = ecrecover(digest, v, r, s);
require(
recoveredAddress != address(0) && recoveredAddress == owner,
"Invalid signature"
);
_approve(owner, spender, amount);
}
/// @notice Creates `amount` tokens and assigns them to `account`,
/// increasing the total supply.
/// @dev Requirements:
/// - `recipient` cannot be the zero address.
function mint(address recipient, uint256 amount) external onlyOwner {
require(recipient != address(0), "Mint to the zero address");
beforeTokenTransfer(address(0), recipient, amount);
totalSupply += amount;
balanceOf[recipient] += amount;
emit Transfer(address(0), recipient, amount);
}
/// @notice Destroys `amount` tokens from the caller.
/// @dev Requirements:
/// - the caller must have a balance of at least `amount`.
function burn(uint256 amount) external override {
_burn(msg.sender, amount);
}
/// @notice Destroys `amount` of tokens from `account` using the allowance
/// mechanism. `amount` is then deducted from the caller's allowance
/// unless the allowance was made for `type(uint256).max`.
/// @dev Requirements:
/// - `account` must have a balance of at least `amount`,
/// - the caller must have allowance for `account`'s tokens of at least
/// `amount`.
function burnFrom(address account, uint256 amount) external override {
uint256 currentAllowance = allowance[account][msg.sender];
if (currentAllowance != type(uint256).max) {
require(
currentAllowance >= amount,
"Burn amount exceeds allowance"
);
_approve(account, msg.sender, currentAllowance - amount);
}
_burn(account, amount);
}
/// @notice Calls `receiveApproval` function on spender previously approving
/// the spender to withdraw from the caller multiple times, up to
/// the `amount` amount. If this function is called again, it
/// overwrites the current allowance with `amount`. Reverts if the
/// approval reverted or if `receiveApproval` call on the spender
/// reverted.
/// @return True if both approval and `receiveApproval` calls succeeded.
/// @dev If the `amount` is set to `type(uint256).max` then
/// `transferFrom` and `burnFrom` will not reduce an allowance.
function approveAndCall(
address spender,
uint256 amount,
bytes memory extraData
) external override returns (bool) {
if (approve(spender, amount)) {
IReceiveApproval(spender).receiveApproval(
msg.sender,
amount,
address(this),
extraData
);
return true;
}
return false;
}
/// @notice Sets `amount` as the allowance of `spender` over the caller's
/// tokens.
/// @return True if the operation succeeded.
/// @dev If the `amount` is set to `type(uint256).max` then
/// `transferFrom` and `burnFrom` will not reduce an allowance.
/// 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
function approve(address spender, uint256 amount)
public
override
returns (bool)
{
_approve(msg.sender, spender, amount);
return true;
}
/// @notice Returns hash of EIP712 Domain struct with the token name as
/// a signing domain and token contract as a verifying contract.
/// Used to construct EIP2612 signature provided to `permit`
/// function.
/* solhint-disable-next-line func-name-mixedcase */
function DOMAIN_SEPARATOR() public view override returns (bytes32) {
// As explained in EIP-2612, if the DOMAIN_SEPARATOR contains the
// chainId and is defined at contract deployment instead of
// reconstructed for every signature, there is a risk of possible replay
// attacks between chains in the event of a future chain split.
// To address this issue, we check the cached chain ID against the
// current one and in case they are different, we build domain separator
// from scratch.
if (block.chainid == cachedChainId) {
return cachedDomainSeparator;
} else {
return buildDomainSeparator();
}
}
/// @dev Hook that is called before any transfer of tokens. This includes
/// minting and burning.
///
/// Calling conditions:
/// - when `from` and `to` are both non-zero, `amount` of `from`'s tokens
/// will be to transferred to `to`.
/// - when `from` is zero, `amount` tokens will be minted for `to`.
/// - when `to` is zero, `amount` of ``from``'s tokens will be burned.
/// - `from` and `to` are never both zero.
// slither-disable-next-line dead-code
function beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
function _burn(address account, uint256 amount) internal {
uint256 currentBalance = balanceOf[account];
require(currentBalance >= amount, "Burn amount exceeds balance");
beforeTokenTransfer(account, address(0), amount);
balanceOf[account] = currentBalance - amount;
totalSupply -= amount;
emit Transfer(account, address(0), amount);
}
function _transfer(
address sender,
address recipient,
uint256 amount
) private {
require(sender != address(0), "Transfer from the zero address");
require(recipient != address(0), "Transfer to the zero address");
require(recipient != address(this), "Transfer to the token address");
beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = balanceOf[sender];
require(senderBalance >= amount, "Transfer amount exceeds balance");
balanceOf[sender] = senderBalance - amount;
balanceOf[recipient] += amount;
emit Transfer(sender, recipient, amount);
}
function _approve(
address owner,
address spender,
uint256 amount
) private {
require(owner != address(0), "Approve from the zero address");
require(spender != address(0), "Approve to the zero address");
allowance[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
function buildDomainSeparator() private view returns (bytes32) {
return
keccak256(
abi.encode(
keccak256(
"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
),
keccak256(bytes(name)),
keccak256(bytes("1")),
block.chainid,
address(this)
)
);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
/// @title MisfundRecovery
/// @notice Allows the owner of the token contract extending MisfundRecovery
/// to recover any ERC20 and ERC721 sent mistakenly to the token
/// contract address.
contract MisfundRecovery is Ownable {
using SafeERC20 for IERC20;
function recoverERC20(
IERC20 token,
address recipient,
uint256 amount
) external onlyOwner {
token.safeTransfer(recipient, amount);
}
function recoverERC721(
IERC721 token,
address recipient,
uint256 tokenId,
bytes calldata data
) external onlyOwner {
token.safeTransferFrom(address(this), recipient, tokenId, data);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../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.
*
* By default, the owner account will be the one that deploys the contract. 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;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_setOwner(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 {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "./IApproveAndCall.sol";
/// @title IERC20WithPermit
/// @notice Burnable ERC20 token with EIP2612 permit functionality. User can
/// authorize a transfer of their token with a signature conforming
/// EIP712 standard instead of an on-chain transaction from their
/// address. Anyone can submit this signature on the user's behalf by
/// calling the permit function, as specified in EIP2612 standard,
/// paying gas fees, and possibly performing other actions in the same
/// transaction.
interface IERC20WithPermit is IERC20, IERC20Metadata, IApproveAndCall {
/// @notice EIP2612 approval made with secp256k1 signature.
/// Users can authorize a transfer of their tokens with a signature
/// conforming EIP712 standard, rather than an on-chain transaction
/// from their address. Anyone can submit this signature on the
/// user's behalf by calling the permit function, paying gas fees,
/// and possibly performing other actions in the same transaction.
/// @dev The deadline argument can be set to `type(uint256).max to create
/// permits that effectively never expire.
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/// @notice Destroys `amount` tokens from the caller.
function burn(uint256 amount) external;
/// @notice Destroys `amount` of tokens from `account`, deducting the amount
/// from caller's allowance.
function burnFrom(address account, uint256 amount) external;
/// @notice Returns hash of EIP712 Domain struct with the token name as
/// a signing domain and token contract as a verifying contract.
/// Used to construct EIP2612 signature provided to `permit`
/// function.
/* solhint-disable-next-line func-name-mixedcase */
function DOMAIN_SEPARATOR() external view returns (bytes32);
/// @notice Returns the current nonce for EIP2612 permission for the
/// provided token owner for a replay protection. Used to construct
/// EIP2612 signature provided to `permit` function.
function nonces(address owner) external view returns (uint256);
/// @notice Returns EIP2612 Permit message hash. Used to construct EIP2612
/// signature provided to `permit` function.
/* solhint-disable-next-line func-name-mixedcase */
function PERMIT_TYPEHASH() external pure returns (bytes32);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
/// @notice An interface that should be implemented by contracts supporting
/// `approveAndCall`/`receiveApproval` pattern.
interface IReceiveApproval {
/// @notice Receives approval to spend tokens. Called as a result of
/// `approveAndCall` call on the token.
function receiveApproval(
address from,
uint256 amount,
address token,
bytes calldata extraData
) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*
* @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;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) 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 `amount` 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 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
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
pragma solidity ^0.8.4;
/// @notice An interface that should be implemented by tokens supporting
/// `approveAndCall`/`receiveApproval` pattern.
interface IApproveAndCall {
/// @notice Executes `receiveApproval` function on spender as specified in
/// `IReceiveApproval` interface. Approves spender to withdraw from
/// the caller multiple times, up to the `amount`. If this
/// function is called again, it overwrites the current allowance
/// with `amount`. Reverts if the approval reverted or if
/// `receiveApproval` call on the spender reverted.
function approveAndCall(
address spender,
uint256 amount,
bytes memory extraData
) external returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 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 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
/**
* @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).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) private pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* 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[EIP 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);
}