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Contract Diff Checker

Contract Name:
ETH20AVATAR

Contract Source Code:

File 1 of 1 : ETH20AVATAR

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity 0.8.19;

/**
 * @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;
    }
}

/**
 * @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() {
        _transferOwnership(_msgSender());
    }

    /**
     * @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 {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @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 {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _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);
    }
}

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return 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 up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev 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 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                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 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv 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.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / 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 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            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 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // 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 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, 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;
        }
    }

    /**
     * @notice 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) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice 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 + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 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 + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * 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 + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * 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;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 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 + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `int256` to its ASCII `string` decimal representation.
     */
    function toString(int256 value) internal pure returns (string memory) {
        return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }

    /**
     * @dev Returns true if the two strings are equal.
     */
    function equal(string memory a, string memory b) internal pure returns (bool) {
        return keccak256(bytes(a)) == keccak256(bytes(b));
    }
}

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV // Deprecated in v4.8
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, "\x19Ethereum Signed Message:\n32")
            mstore(0x1c, hash)
            message := keccak256(0x00, 0x3c)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
        /// @solidity memory-safe-assembly
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, "\x19\x01")
            mstore(add(ptr, 0x02), domainSeparator)
            mstore(add(ptr, 0x22), structHash)
            data := keccak256(ptr, 0x42)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Data with intended validator, created from a
     * `validator` and `data` according to the version 0 of EIP-191.
     *
     * See {recover}.
     */
    function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x00", validator, data));
    }
}

/// The ERC721 standard allows for self-approvals.
/// For performance, this implementation WILL NOT revert for such actions.
/// Please add any checks with overrides if desired.
abstract contract ERC721 {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         CONSTANTS                          */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev An account can hold up to 4294967295 tokens.
    uint256 internal constant _MAX_ACCOUNT_BALANCE = 0xffffffff;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       CUSTOM ERRORS                        */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Only the token owner or an approved account can manage the token.
    error NotOwnerNorApproved();

    /// @dev The token does not exist.
    error TokenDoesNotExist();

    /// @dev The token already exists.
    error TokenAlreadyExists();

    /// @dev Cannot query the balance for the zero address.
    error BalanceQueryForZeroAddress();

    /// @dev Cannot mint or transfer to the zero address.
    error TransferToZeroAddress();

    /// @dev The token must be owned by `from`.
    error TransferFromIncorrectOwner();

    /// @dev The recipient's balance has overflowed.
    error AccountBalanceOverflow();

    /// @dev Cannot safely transfer to a contract that does not implement
    /// the ERC721Receiver interface.
    error TransferToNonERC721ReceiverImplementer();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                           EVENTS                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Emitted when token `id` is transferred from `from` to `to`.
    event Transfer(address indexed from, address indexed to, uint256 indexed id);

    /// @dev Emitted when `owner` enables `account` to manage the `id` token.
    event Approval(address indexed owner, address indexed account, uint256 indexed id);

    /// @dev Emitted when `owner` enables or disables `operator` to manage all of their tokens.
    event ApprovalForAll(address indexed owner, address indexed operator, bool isApproved);

    /// @dev `keccak256(bytes("Transfer(address,address,uint256)"))`.
    uint256 private constant _TRANSFER_EVENT_SIGNATURE =
        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

    /// @dev `keccak256(bytes("Approval(address,address,uint256)"))`.
    uint256 private constant _APPROVAL_EVENT_SIGNATURE =
        0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925;

    /// @dev `keccak256(bytes("ApprovalForAll(address,address,bool)"))`.
    uint256 private constant _APPROVAL_FOR_ALL_EVENT_SIGNATURE =
        0x17307eab39ab6107e8899845ad3d59bd9653f200f220920489ca2b5937696c31;

    // =============================================================
    //                          CONSTRUCTOR
    // =============================================================

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                          STORAGE                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The ownership data slot of `id` is given by:
    /// ```
    ///     mstore(0x00, id)
    ///     mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
    ///     let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
    /// ```
    /// Bits Layout:
    // - [0..159]   `addr`
    // - [160..223] `extraData`
    ///
    /// The approved address slot is given by: `add(1, ownershipSlot)`.
    ///
    /// See: https://notes.ethereum.org/%40vbuterin/verkle_tree_eip
    ///
    /// The balance slot of `owner` is given by:
    /// ```
    ///     mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
    ///     mstore(0x00, owner)
    ///     let balanceSlot := keccak256(0x0c, 0x1c)
    /// ```
    /// Bits Layout:
    /// - [0..31]   `balance`
    /// - [32..225] `aux`
    ///
    /// The `operator` approval slot of `owner` is given by:
    /// ```
    ///     mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, operator))
    ///     mstore(0x00, owner)
    ///     let operatorApprovalSlot := keccak256(0x0c, 0x30)
    /// ```
    uint256 private constant _ERC721_MASTER_SLOT_SEED = 0x7d8825530a5a2e7a << 192;

    /// @dev Pre-shifted and pre-masked constant.
    uint256 private constant _ERC721_MASTER_SLOT_SEED_MASKED = 0x0a5a2e7a00000000;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                      ERC721 METADATA                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the token collection name.
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /// @dev Returns the token collection symbol.
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /// @dev Returns the Uniform Resource Identifier (URI) for token `id`.
    function tokenURI(uint256 tokenId) public view virtual returns (string memory) {
        if (!_exists(tokenId)) revert TokenDoesNotExist();

        string memory baseURI = _baseURI();
        return
            bytes(baseURI).length > 0
                ? string(abi.encodePacked(baseURI, "/", _toHexString(address(this)), "/", _toString(tokenId)))
                : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, it can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                           ERC721                           */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the owner of token `id`.
    ///
    /// Requirements:
    /// - Token `id` must exist.
    function ownerOf(uint256 id) public view virtual returns (address result) {
        result = _ownerOf(id);
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(result) {
                mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Returns the number of tokens owned by `owner`.
    ///
    /// Requirements:
    /// - `owner` must not be the zero address.
    function balanceOf(address owner) public view virtual returns (uint256 result) {
        /// @solidity memory-safe-assembly
        assembly {
            // Revert if the `owner` is the zero address.
            if iszero(owner) {
                mstore(0x00, 0x8f4eb604) // `BalanceQueryForZeroAddress()`.
                revert(0x1c, 0x04)
            }
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            mstore(0x00, owner)
            result := and(sload(keccak256(0x0c, 0x1c)), _MAX_ACCOUNT_BALANCE)
        }
    }

    /// @dev Returns the account approved to managed token `id`.
    ///
    /// Requirements:
    /// - Token `id` must exist.
    function getApproved(uint256 id) public view virtual returns (address result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            if iszero(shr(96, shl(96, sload(ownershipSlot)))) {
                mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                revert(0x1c, 0x04)
            }
            result := sload(add(1, ownershipSlot))
        }
    }

    /// @dev Sets `account` as the approved account to manage token `id`.
    ///
    /// Requirements:
    /// - Token `id` must exist.
    /// - The caller must be the owner of the token,
    ///   or an approved operator for the token owner.
    ///
    /// Emits a {Approval} event.
    function approve(address account, uint256 id) public payable virtual {
        _approve(msg.sender, account, id);
    }

    /// @dev Returns whether `operator` is approved to manage the tokens of `owner`.
    function isApprovedForAll(address owner, address operator) public view virtual returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x1c, operator)
            mstore(0x08, _ERC721_MASTER_SLOT_SEED_MASKED)
            mstore(0x00, owner)
            result := sload(keccak256(0x0c, 0x30))
        }
    }

    /// @dev Sets whether `operator` is approved to manage the tokens of the caller.
    ///
    /// Emits a {ApprovalForAll} event.
    function setApprovalForAll(address operator, bool isApproved) public virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // Convert to 0 or 1.
            isApproved := iszero(iszero(isApproved))
            // Update the `isApproved` for (`msg.sender`, `operator`).
            mstore(0x1c, operator)
            mstore(0x08, _ERC721_MASTER_SLOT_SEED_MASKED)
            mstore(0x00, caller())
            sstore(keccak256(0x0c, 0x30), isApproved)
            // Emit the {ApprovalForAll} event.
            mstore(0x00, isApproved)
            log3(0x00, 0x20, _APPROVAL_FOR_ALL_EVENT_SIGNATURE, caller(), shr(96, shl(96, operator)))
        }
    }

    /// @dev Transfers token `id` from `from` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - `from` must be the owner of the token.
    /// - `to` cannot be the zero address.
    /// - The caller must be the owner of the token, or be approved to manage the token.
    ///
    /// Emits a {Transfer} event.
    function transferFrom(address from, address to, uint256 id) public payable virtual {
        _beforeTokenTransfer(from, to, id);
        /// @solidity memory-safe-assembly
        assembly {
            // Clear the upper 96 bits.
            let bitmaskAddress := shr(96, not(0))
            from := and(bitmaskAddress, from)
            to := and(bitmaskAddress, to)
            // Load the ownership data.
            mstore(0x00, id)
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, caller()))
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let ownershipPacked := sload(ownershipSlot)
            let owner := and(bitmaskAddress, ownershipPacked)
            // Revert if `from` is not the owner, or does not exist.
            if iszero(mul(owner, eq(owner, from))) {
                if iszero(owner) {
                    mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                    revert(0x1c, 0x04)
                }
                mstore(0x00, 0xa1148100) // `TransferFromIncorrectOwner()`.
                revert(0x1c, 0x04)
            }
            // Revert if `to` is the zero address.
            if iszero(to) {
                mstore(0x00, 0xea553b34) // `TransferToZeroAddress()`.
                revert(0x1c, 0x04)
            }
            // Load, check, and update the token approval.
            {
                mstore(0x00, from)
                let approvedAddress := sload(add(1, ownershipSlot))
                // Revert if the caller is not the owner, nor approved.
                if iszero(or(eq(caller(), from), eq(caller(), approvedAddress))) {
                    if iszero(sload(keccak256(0x0c, 0x30))) {
                        mstore(0x00, 0x4b6e7f18) // `NotOwnerNorApproved()`.
                        revert(0x1c, 0x04)
                    }
                }
                // Delete the approved address if any.
                if approvedAddress {
                    sstore(add(1, ownershipSlot), 0)
                }
            }
            // Update with the new owner.
            sstore(ownershipSlot, xor(ownershipPacked, xor(from, to)))
            // Decrement the balance of `from`.
            {
                let fromBalanceSlot := keccak256(0x0c, 0x1c)
                sstore(fromBalanceSlot, sub(sload(fromBalanceSlot), 1))
            }
            // Increment the balance of `to`.
            {
                mstore(0x00, to)
                let toBalanceSlot := keccak256(0x0c, 0x1c)
                let toBalanceSlotPacked := add(sload(toBalanceSlot), 1)
                if iszero(and(toBalanceSlotPacked, _MAX_ACCOUNT_BALANCE)) {
                    mstore(0x00, 0x01336cea) // `AccountBalanceOverflow()`.
                    revert(0x1c, 0x04)
                }
                sstore(toBalanceSlot, toBalanceSlotPacked)
            }
            // Emit the {Transfer} event.
            log4(0x00, 0x00, _TRANSFER_EVENT_SIGNATURE, from, to, id)
        }
        _afterTokenTransfer(from, to, id);
    }

    /// @dev Equivalent to `safeTransferFrom(from, to, id, "")`.
    function safeTransferFrom(address from, address to, uint256 id) public payable virtual {
        transferFrom(from, to, id);
        if (_hasCode(to)) _checkOnERC721Received(from, to, id, "");
    }

    /// @dev Transfers token `id` from `from` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - `from` must be the owner of the token.
    /// - `to` cannot be the zero address.
    /// - The caller must be the owner of the token, or be approved to manage the token.
    /// - 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 id, bytes calldata data) public payable virtual {
        transferFrom(from, to, id);
        if (_hasCode(to)) _checkOnERC721Received(from, to, id, data);
    }

    /// @dev Returns true if this contract implements the interface defined by `interfaceId`.
    /// See: https://eips.ethereum.org/EIPS/eip-165
    /// This function call must use less than 30000 gas.
    function supportsInterface(bytes4 interfaceId) public view virtual returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            let s := shr(224, interfaceId)
            // ERC165: 0x01ffc9a7, ERC721: 0x80ac58cd, ERC721Metadata: 0x5b5e139f.
            result := or(or(eq(s, 0x01ffc9a7), eq(s, 0x80ac58cd)), eq(s, 0x5b5e139f))
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  INTERNAL QUERY FUNCTIONS                  */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns if token `id` exists.
    function _exists(uint256 id) internal view virtual returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            result := shl(96, sload(add(id, add(id, keccak256(0x00, 0x20)))))
        }
    }

    /// @dev Returns the owner of token `id`.
    /// Returns the zero address instead of reverting if the token does not exist.
    function _ownerOf(uint256 id) internal view virtual returns (address result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            result := shr(96, shl(96, sload(add(id, add(id, keccak256(0x00, 0x20))))))
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*            INTERNAL DATA HITCHHIKING FUNCTIONS             */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the auxiliary data for `owner`.
    /// Minting, transferring, burning the tokens of `owner` will not change the auxiliary data.
    /// Auxiliary data can be set for any address, even if it does not have any tokens.
    function _getAux(address owner) internal view virtual returns (uint224 result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            mstore(0x00, owner)
            result := shr(32, sload(keccak256(0x0c, 0x1c)))
        }
    }

    /// @dev Set the auxiliary data for `owner` to `value`.
    /// Minting, transferring, burning the tokens of `owner` will not change the auxiliary data.
    /// Auxiliary data can be set for any address, even if it does not have any tokens.
    function _setAux(address owner, uint224 value) internal virtual {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            mstore(0x00, owner)
            let balanceSlot := keccak256(0x0c, 0x1c)
            let packed := sload(balanceSlot)
            sstore(balanceSlot, xor(packed, shl(32, xor(value, shr(32, packed)))))
        }
    }

    /// @dev Returns the extra data for token `id`.
    /// Minting, transferring, burning a token will not change the extra data.
    /// The extra data can be set on a non existent token.
    function _getExtraData(uint256 id) internal view virtual returns (uint96 result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            result := shr(160, sload(add(id, add(id, keccak256(0x00, 0x20)))))
        }
    }

    /// @dev Sets the extra data for token `id` to `value`.
    /// Minting, transferring, burning a token will not change the extra data.
    /// The extra data can be set on a non existent token.
    function _setExtraData(uint256 id, uint96 value) internal virtual {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let packed := sload(ownershipSlot)
            sstore(ownershipSlot, xor(packed, shl(160, xor(value, shr(160, packed)))))
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  INTERNAL MINT FUNCTIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Mints token `id` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must not exist.
    /// - `to` cannot be the zero address.
    ///
    /// Emits a {Transfer} event.
    function _mint(address to, uint256 id) internal virtual {
        _beforeTokenTransfer(address(0), to, id);
        /// @solidity memory-safe-assembly
        assembly {
            // Clear the upper 96 bits.
            to := shr(96, shl(96, to))
            // Revert if `to` is the zero address.
            if iszero(to) {
                mstore(0x00, 0xea553b34) // `TransferToZeroAddress()`.
                revert(0x1c, 0x04)
            }
            // Load the ownership data.
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let ownershipPacked := sload(ownershipSlot)
            // Revert if the token already exists.
            if shl(96, ownershipPacked) {
                mstore(0x00, 0xc991cbb1) // `TokenAlreadyExists()`.
                revert(0x1c, 0x04)
            }
            // Update with the owner.
            sstore(ownershipSlot, or(ownershipPacked, to))
            // Increment the balance of the owner.
            {
                mstore(0x00, to)
                let balanceSlot := keccak256(0x0c, 0x1c)
                let balanceSlotPacked := add(sload(balanceSlot), 1)
                if iszero(and(balanceSlotPacked, _MAX_ACCOUNT_BALANCE)) {
                    mstore(0x00, 0x01336cea) // `AccountBalanceOverflow()`.
                    revert(0x1c, 0x04)
                }
                sstore(balanceSlot, balanceSlotPacked)
            }
            // Emit the {Transfer} event.
            log4(0x00, 0x00, _TRANSFER_EVENT_SIGNATURE, 0, to, id)
        }
        _afterTokenTransfer(address(0), to, id);
    }

    /// @dev Equivalent to `_safeMint(to, id, "")`.
    function _safeMint(address to, uint256 id) internal virtual {
        _safeMint(to, id, "");
    }

    /// @dev Mints token `id` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must not exist.
    /// - `to` cannot be the zero address.
    /// - If `to` refers to a smart contract, it must implement
    ///   {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
    ///
    /// Emits a {Transfer} event.
    function _safeMint(address to, uint256 id, bytes memory data) internal virtual {
        _mint(to, id);
        if (_hasCode(to)) _checkOnERC721Received(address(0), to, id, data);
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  INTERNAL BURN FUNCTIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Equivalent to `_burn(address(0), id)`.
    function _burn(uint256 id) internal virtual {
        _burn(address(0), id);
    }

    /// @dev Destroys token `id`, using `by`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - If `by` is not the zero address,
    ///   it must be the owner of the token, or be approved to manage the token.
    ///
    /// Emits a {Transfer} event.
    function _burn(address by, uint256 id) internal virtual {
        address owner = ownerOf(id);
        _beforeTokenTransfer(owner, address(0), id);
        /// @solidity memory-safe-assembly
        assembly {
            // Clear the upper 96 bits.
            by := shr(96, shl(96, by))
            // Load the ownership data.
            mstore(0x00, id)
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, by))
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let ownershipPacked := sload(ownershipSlot)
            // Reload the owner in case it is changed in `_beforeTokenTransfer`.
            owner := shr(96, shl(96, ownershipPacked))
            // Revert if the token does not exist.
            if iszero(owner) {
                mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                revert(0x1c, 0x04)
            }
            // Load and check the token approval.
            {
                mstore(0x00, owner)
                let approvedAddress := sload(add(1, ownershipSlot))
                // If `by` is not the zero address, do the authorization check.
                // Revert if the `by` is not the owner, nor approved.
                if iszero(or(iszero(by), or(eq(by, owner), eq(by, approvedAddress)))) {
                    if iszero(sload(keccak256(0x0c, 0x30))) {
                        mstore(0x00, 0x4b6e7f18) // `NotOwnerNorApproved()`.
                        revert(0x1c, 0x04)
                    }
                }
                // Delete the approved address if any.
                if approvedAddress {
                    sstore(add(1, ownershipSlot), 0)
                }
            }
            // Clear the owner.
            sstore(ownershipSlot, xor(ownershipPacked, owner))
            // Decrement the balance of `owner`.
            {
                let balanceSlot := keccak256(0x0c, 0x1c)
                sstore(balanceSlot, sub(sload(balanceSlot), 1))
            }
            // Emit the {Transfer} event.
            log4(0x00, 0x00, _TRANSFER_EVENT_SIGNATURE, owner, 0, id)
        }
        _afterTokenTransfer(owner, address(0), id);
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                INTERNAL APPROVAL FUNCTIONS                 */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns whether `account` is the owner of token `id`, or is approved to managed it.
    ///
    /// Requirements:
    /// - Token `id` must exist.
    function _isApprovedOrOwner(address account, uint256 id) internal view virtual returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := 1
            // Clear the upper 96 bits.
            account := shr(96, shl(96, account))
            // Load the ownership data.
            mstore(0x00, id)
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, account))
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let owner := shr(96, shl(96, sload(ownershipSlot)))
            // Revert if the token does not exist.
            if iszero(owner) {
                mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                revert(0x1c, 0x04)
            }
            // Check if `account` is the `owner`.
            if iszero(eq(account, owner)) {
                mstore(0x00, owner)
                // Check if `account` is approved to
                if iszero(sload(keccak256(0x0c, 0x30))) {
                    result := eq(account, sload(add(1, ownershipSlot)))
                }
            }
        }
    }

    /// @dev Returns the account approved to manage token `id`.
    /// Returns the zero address instead of reverting if the token does not exist.
    function _getApproved(uint256 id) internal view virtual returns (address result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, id)
            mstore(0x1c, _ERC721_MASTER_SLOT_SEED)
            result := sload(add(1, add(id, add(id, keccak256(0x00, 0x20)))))
        }
    }

    /// @dev Equivalent to `_approve(address(0), account, id)`.
    function _approve(address account, uint256 id) internal virtual {
        _approve(address(0), account, id);
    }

    /// @dev Sets `account` as the approved account to manage token `id`, using `by`.
    ///
    /// Requirements:
    /// - Token `id` must exist.
    /// - If `by` is not the zero address, `by` must be the owner
    ///   or an approved operator for the token owner.
    ///
    /// Emits a {Transfer} event.
    function _approve(address by, address account, uint256 id) internal virtual {
        assembly {
            // Clear the upper 96 bits.
            let bitmaskAddress := shr(96, not(0))
            account := and(bitmaskAddress, account)
            by := and(bitmaskAddress, by)
            // Load the owner of the token.
            mstore(0x00, id)
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, by))
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let owner := and(bitmaskAddress, sload(ownershipSlot))
            // Revert if the token does not exist.
            if iszero(owner) {
                mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                revert(0x1c, 0x04)
            }
            // If `by` is not the zero address, do the authorization check.
            // Revert if `by` is not the owner, nor approved.
            if iszero(or(iszero(by), eq(by, owner))) {
                mstore(0x00, owner)
                if iszero(sload(keccak256(0x0c, 0x30))) {
                    mstore(0x00, 0x4b6e7f18) // `NotOwnerNorApproved()`.
                    revert(0x1c, 0x04)
                }
            }
            // Sets `account` as the approved account to manage `id`.
            sstore(add(1, ownershipSlot), account)
            // Emit the {Approval} event.
            log4(0x00, 0x00, _APPROVAL_EVENT_SIGNATURE, owner, account, id)
        }
    }

    /// @dev Approve or remove the `operator` as an operator for `by`,
    /// without authorization checks.
    ///
    /// Emits a {ApprovalForAll} event.
    function _setApprovalForAll(address by, address operator, bool isApproved) internal virtual {
        /// @solidity memory-safe-assembly
        assembly {
            // Clear the upper 96 bits.
            by := shr(96, shl(96, by))
            operator := shr(96, shl(96, operator))
            // Convert to 0 or 1.
            isApproved := iszero(iszero(isApproved))
            // Update the `isApproved` for (`by`, `operator`).
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, operator))
            mstore(0x00, by)
            sstore(keccak256(0x0c, 0x30), isApproved)
            // Emit the {ApprovalForAll} event.
            mstore(0x00, isApproved)
            log3(0x00, 0x20, _APPROVAL_FOR_ALL_EVENT_SIGNATURE, by, operator)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                INTERNAL TRANSFER FUNCTIONS                 */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Equivalent to `_transfer(address(0), from, to, id)`.
    function _transfer(address from, address to, uint256 id) internal virtual {
        _transfer(address(0), from, to, id);
    }

    /// @dev Transfers token `id` from `from` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - `from` must be the owner of the token.
    /// - `to` cannot be the zero address.
    /// - If `by` is not the zero address,
    ///   it must be the owner of the token, or be approved to manage the token.
    ///
    /// Emits a {Transfer} event.
    function _transfer(address by, address from, address to, uint256 id) internal virtual {
        _beforeTokenTransfer(from, to, id);
        /// @solidity memory-safe-assembly
        assembly {
            // Clear the upper 96 bits.
            let bitmaskAddress := shr(96, not(0))
            from := and(bitmaskAddress, from)
            to := and(bitmaskAddress, to)
            by := and(bitmaskAddress, by)
            // Load the ownership data.
            mstore(0x00, id)
            mstore(0x1c, or(_ERC721_MASTER_SLOT_SEED, by))
            let ownershipSlot := add(id, add(id, keccak256(0x00, 0x20)))
            let ownershipPacked := sload(ownershipSlot)
            let owner := and(bitmaskAddress, ownershipPacked)
            // Revert if `from` is not the owner, or does not exist.
            if iszero(mul(owner, eq(owner, from))) {
                if iszero(owner) {
                    mstore(0x00, 0xceea21b6) // `TokenDoesNotExist()`.
                    revert(0x1c, 0x04)
                }
                mstore(0x00, 0xa1148100) // `TransferFromIncorrectOwner()`.
                revert(0x1c, 0x04)
            }
            // Revert if `to` is the zero address.
            if iszero(to) {
                mstore(0x00, 0xea553b34) // `TransferToZeroAddress()`.
                revert(0x1c, 0x04)
            }
            // Load, check, and update the token approval.
            {
                mstore(0x00, from)
                let approvedAddress := sload(add(1, ownershipSlot))
                // If `by` is not the zero address, do the authorization check.
                // Revert if the `by` is not the owner, nor approved.
                if iszero(or(iszero(by), or(eq(by, from), eq(by, approvedAddress)))) {
                    if iszero(sload(keccak256(0x0c, 0x30))) {
                        mstore(0x00, 0x4b6e7f18) // `NotOwnerNorApproved()`.
                        revert(0x1c, 0x04)
                    }
                }
                // Delete the approved address if any.
                if approvedAddress {
                    sstore(add(1, ownershipSlot), 0)
                }
            }
            // Update with the new owner.
            sstore(ownershipSlot, xor(ownershipPacked, xor(from, to)))
            // Decrement the balance of `from`.
            {
                let fromBalanceSlot := keccak256(0x0c, 0x1c)
                sstore(fromBalanceSlot, sub(sload(fromBalanceSlot), 1))
            }
            // Increment the balance of `to`.
            {
                mstore(0x00, to)
                let toBalanceSlot := keccak256(0x0c, 0x1c)
                let toBalanceSlotPacked := add(sload(toBalanceSlot), 1)
                if iszero(and(toBalanceSlotPacked, _MAX_ACCOUNT_BALANCE)) {
                    mstore(0x00, 0x01336cea) // `AccountBalanceOverflow()`.
                    revert(0x1c, 0x04)
                }
                sstore(toBalanceSlot, toBalanceSlotPacked)
            }
            // Emit the {Transfer} event.
            log4(0x00, 0x00, _TRANSFER_EVENT_SIGNATURE, from, to, id)
        }
        _afterTokenTransfer(from, to, id);
    }

    /// @dev Equivalent to `_safeTransfer(from, to, id, "")`.
    function _safeTransfer(address from, address to, uint256 id) internal virtual {
        _safeTransfer(from, to, id, "");
    }

    /// @dev Transfers token `id` from `from` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - `from` must be the owner of the token.
    /// - `to` cannot be the zero address.
    /// - The caller must be the owner of the token, or be approved to manage the token.
    /// - If `to` refers to a smart contract, it must implement
    ///   {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
    ///
    /// Emits a {Transfer} event.
    function _safeTransfer(address from, address to, uint256 id, bytes memory data) internal virtual {
        _transfer(address(0), from, to, id);
        if (_hasCode(to)) _checkOnERC721Received(from, to, id, data);
    }

    /// @dev Equivalent to `_safeTransfer(by, from, to, id, "")`.
    function _safeTransfer(address by, address from, address to, uint256 id) internal virtual {
        _safeTransfer(by, from, to, id, "");
    }

    /// @dev Transfers token `id` from `from` to `to`.
    ///
    /// Requirements:
    ///
    /// - Token `id` must exist.
    /// - `from` must be the owner of the token.
    /// - `to` cannot be the zero address.
    /// - If `by` is not the zero address,
    ///   it must be the owner of the token, or be approved to manage the token.
    /// - If `to` refers to a smart contract, it must implement
    ///   {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
    ///
    /// Emits a {Transfer} event.
    function _safeTransfer(address by, address from, address to, uint256 id, bytes memory data) internal virtual {
        _transfer(by, from, to, id);
        if (_hasCode(to)) _checkOnERC721Received(from, to, id, data);
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                    HOOKS FOR OVERRIDING                    */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Hook that is called before any token transfers, including minting and burning.
    function _beforeTokenTransfer(address from, address to, uint256 id) internal virtual {}

    /// @dev Hook that is called after any token transfers, including minting and burning.
    function _afterTokenTransfer(address from, address to, uint256 id) internal virtual {}

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                      PRIVATE HELPERS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns if `a` has bytecode of non-zero length.
    function _hasCode(address a) private view returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := extcodesize(a) // Can handle dirty upper bits.
        }
    }

    /// @dev Perform a call to invoke {IERC721Receiver-onERC721Received} on `to`.
    /// Reverts if the target does not support the function correctly.
    function _checkOnERC721Received(address from, address to, uint256 id, bytes memory data) private {
        /// @solidity memory-safe-assembly
        assembly {
            // Prepare the calldata.
            let m := mload(0x40)
            let onERC721ReceivedSelector := 0x150b7a02
            mstore(m, onERC721ReceivedSelector)
            mstore(add(m, 0x20), caller()) // The `operator`, which is always `msg.sender`.
            mstore(add(m, 0x40), shr(96, shl(96, from)))
            mstore(add(m, 0x60), id)
            mstore(add(m, 0x80), 0x80)
            let n := mload(data)
            mstore(add(m, 0xa0), n)
            if n {
                pop(staticcall(gas(), 4, add(data, 0x20), n, add(m, 0xc0), n))
            }
            // Revert if the call reverts.
            if iszero(call(gas(), to, 0, add(m, 0x1c), add(n, 0xa4), m, 0x20)) {
                if returndatasize() {
                    // Bubble up the revert if the call reverts.
                    returndatacopy(0x00, 0x00, returndatasize())
                    revert(0x00, returndatasize())
                }
                mstore(m, 0)
            }
            // Load the returndata and compare it.
            if iszero(eq(mload(m), shl(224, onERC721ReceivedSelector))) {
                mstore(0x00, 0xd1a57ed6) // `TransferToNonERC721ReceiverImplementer()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /**
     * @dev Converts a uint256 to its ASCII string decimal representation.
     */
    function _toString(uint256 value) internal pure virtual returns (string memory str) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
            // We will need 1 word for the trailing zeros padding, 1 word for the length,
            // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
            let m := add(mload(0x40), 0xa0)
            // Update the free memory pointer to allocate.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end of the memory to calculate the length later.
            let end := str

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is prefixed with "0x" and encoded using 2 hexadecimal digits per byte.
    function _toHexString(address value) internal pure returns (string memory str) {
        str = _toHexStringNoPrefix(value);
        /// @solidity memory-safe-assembly
        assembly {
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(str, 0x3078) // Write the "0x" prefix.
            str := sub(str, 2) // Move the pointer.
            mstore(str, strLength) // Write the length.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is encoded using 2 hexadecimal digits per byte.
    function _toHexStringNoPrefix(address value) internal pure returns (string memory str) {
        /// @solidity memory-safe-assembly
        assembly {
            str := mload(0x40)

            // Allocate the memory.
            // We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
            // 0x02 bytes for the prefix, and 0x28 bytes for the digits.
            // The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x28) is 0x80.
            mstore(0x40, add(str, 0x80))

            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            str := add(str, 2)
            mstore(str, 40)

            let o := add(str, 0x20)
            mstore(add(o, 40), 0)

            value := shl(96, value)

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            for {
                let i := 0
            } 1 {

            } {
                let p := add(o, add(i, i))
                let temp := byte(i, value)
                mstore8(add(p, 1), mload(and(temp, 15)))
                mstore8(p, mload(shr(4, temp)))
                i := add(i, 1)
                if eq(i, 20) {
                    break
                }
            }
        }
    }
}

/**
 * @dev Interface of ERC721ABurnable.
 */
interface IERC721Burnable {
    /**
     * @dev Burns `tokenId`. See {ERC721A-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) external;
}

/**
 * @title ERC721Burnable.
 *
 * @dev ERC721 token that can be irreversibly burned (destroyed).
 */
abstract contract ERC721Burnable is ERC721, IERC721Burnable {
    /**
     * @dev Burns `tokenId`. See {ERC721-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) public virtual override {
        _burn(tokenId);
    }
}

/// @notice Based on the reference implementation of the EIP-4494
/// @notice See https://github.com/dievardump/erc721-with-permits and https://eips.ethereum.org/EIPS/eip-4494
/// @author Simon Fremaux (@dievardump) & William SchwabSchwab (@wschwab)
interface IERC4494 {
    function DOMAIN_SEPARATOR() external view returns (bytes32);

    /// @notice Allows to retrieve current nonce for token
    /// @param tokenId token id
    /// @return current token nonce
    function nonces(uint256 tokenId) external view returns (uint256);

    /// @notice function to be called by anyone to approve `spender` using a Permit signature
    /// @dev Anyone can call this to approve `spender`, even a third-party
    /// @param spender the actor to approve
    /// @param tokenId the token id
    /// @param deadline the deadline for the permit to be used
    /// @param signature permit
    function permit(address spender, uint256 tokenId, uint256 deadline, bytes memory signature) external;
}

/// @notice Contract for EIP-712 typed structured data hashing and signing.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/EIP712.sol)
/// @author Modified from Solbase (https://github.com/Sol-DAO/solbase/blob/main/src/utils/EIP712.sol)
/// @author Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/cryptography/EIP712.sol)
/// Note, this implementation:
/// - Uses `address(this)` for the `verifyingContract` field.
/// - Does NOT use the optional EIP-712 salt.
/// - Does NOT use any EIP-712 extensions.
/// This is for simplicity and to save gas.
/// If you need to customize, please fork / modify accordingly.
abstract contract EIP712 {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                  CONSTANTS AND IMMUTABLES                  */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev `keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")`.
    bytes32 internal constant _DOMAIN_TYPEHASH = 0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f;

    address private immutable _cachedThis;
    uint256 private immutable _cachedChainId;
    bytes32 private immutable _cachedNameHash;
    bytes32 private immutable _cachedVersionHash;
    bytes32 private immutable _cachedDomainSeparator;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                        CONSTRUCTOR                         */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Cache the hashes for cheaper runtime gas costs.
    /// In the case of upgradeable contracts (i.e. proxies),
    /// or if the chain id changes due to a hard fork,
    /// the domain separator will be seamlessly calculated on-the-fly.
    constructor() {
        _cachedThis = address(this);
        _cachedChainId = block.chainid;

        (string memory name, string memory version) = _domainNameAndVersion();
        bytes32 nameHash = keccak256(bytes(name));
        bytes32 versionHash = keccak256(bytes(version));
        _cachedNameHash = nameHash;
        _cachedVersionHash = versionHash;

        bytes32 separator;
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Load the free memory pointer.
            mstore(m, _DOMAIN_TYPEHASH)
            mstore(add(m, 0x20), nameHash)
            mstore(add(m, 0x40), versionHash)
            mstore(add(m, 0x60), chainid())
            mstore(add(m, 0x80), address())
            separator := keccak256(m, 0xa0)
        }
        _cachedDomainSeparator = separator;
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   FUNCTIONS TO OVERRIDE                    */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Please override this function to return the domain name and version.
    /// ```
    ///     function _domainNameAndVersion()
    ///         internal
    ///         pure
    ///         virtual
    ///         returns (string memory name, string memory version)
    ///     {
    ///         name = "Solady";
    ///         version = "1";
    ///     }
    /// ```
    function _domainNameAndVersion() internal pure virtual returns (string memory name, string memory version);

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                     HASHING OPERATIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the EIP-712 domain separator.
    function _domainSeparator() internal view virtual returns (bytes32 separator) {
        separator = _cachedDomainSeparator;
        if (_cachedDomainSeparatorInvalidated()) {
            separator = _buildDomainSeparator();
        }
    }

    /// @dev Returns the hash of the fully encoded EIP-712 message for this domain,
    /// given `structHash`, as defined in
    /// https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct.
    ///
    /// The hash can be used together with {ECDSA-recover} to obtain the signer of a message:
    /// ```
    ///     bytes32 digest = _hashTypedData(keccak256(abi.encode(
    ///         keccak256("Mail(address to,string contents)"),
    ///         mailTo,
    ///         keccak256(bytes(mailContents))
    ///     )));
    ///     address signer = ECDSA.recover(digest, signature);
    /// ```
    function _hashTypedData(bytes32 structHash) internal view virtual returns (bytes32 digest) {
        bytes32 separator = _cachedDomainSeparator;
        if (_cachedDomainSeparatorInvalidated()) {
            separator = _buildDomainSeparator();
        }
        /// @solidity memory-safe-assembly
        assembly {
            // Compute the digest.
            mstore(0x00, 0x1901000000000000) // Store "\x19\x01".
            mstore(0x1a, separator) // Store the domain separator.
            mstore(0x3a, structHash) // Store the struct hash.
            digest := keccak256(0x18, 0x42)
            // Restore the part of the free memory slot that was overwritten.
            mstore(0x3a, 0)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                    EIP-5267 OPERATIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev See: https://eips.ethereum.org/EIPS/eip-5267
    function eip712Domain()
        public
        view
        virtual
        returns (
            bytes1 fields,
            string memory name,
            string memory version,
            uint256 chainId,
            address verifyingContract,
            bytes32 salt,
            uint256[] memory extensions
        )
    {
        fields = hex"0f"; // `0b01111`.
        (name, version) = _domainNameAndVersion();
        chainId = block.chainid;
        verifyingContract = address(this);
        salt = salt; // `bytes32(0)`.
        extensions = extensions; // `new uint256[](0)`.
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                      PRIVATE HELPERS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the EIP-712 domain separator.
    function _buildDomainSeparator() private view returns (bytes32 separator) {
        bytes32 nameHash = _cachedNameHash;
        bytes32 versionHash = _cachedVersionHash;
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Load the free memory pointer.
            mstore(m, _DOMAIN_TYPEHASH)
            mstore(add(m, 0x20), nameHash)
            mstore(add(m, 0x40), versionHash)
            mstore(add(m, 0x60), chainid())
            mstore(add(m, 0x80), address())
            separator := keccak256(m, 0xa0)
        }
    }

    /// @dev Returns if the cached domain separator has been invalidated.
    function _cachedDomainSeparatorInvalidated() private view returns (bool result) {
        uint256 cachedChainId = _cachedChainId;
        address cachedThis = _cachedThis;
        /// @solidity memory-safe-assembly
        assembly {
            result := iszero(and(eq(chainid(), cachedChainId), eq(address(), cachedThis)))
        }
    }
}

/// @dev OpenZeppelin's ERC721Upgradeable extended with EIP-4494-compliant permits
/// @notice Based on the reference implementation of the EIP-4494
/// @notice See https://github.com/dievardump/erc721-with-permits and https://eips.ethereum.org/EIPS/eip-4494
abstract contract ERC721Permit is IERC4494, EIP712, ERC721 {
    /// @dev value is equal to keccak256("Permit(address spender,uint256 tokenId,uint256 nonce,uint256 deadline)")
    bytes32 public constant PERMIT_TYPEHASH = 0x49ecf333e5b8c95c40fdafc95c1ad136e8914a8fb55e9dc8bb01eaa83a2df9ad;

    mapping(uint256 => uint256) internal _nonces;

    /// @notice Builds the DOMAIN_SEPARATOR (eip712) at time of use
    /// @dev This is not set as a constant, to ensure that the chainId will change in the event of a chain fork
    /// @return the DOMAIN_SEPARATOR of eip712
    function DOMAIN_SEPARATOR() public view override returns (bytes32) {
        return _domainSeparator();
    }

    /// @notice Allows to retrieve current nonce for token
    /// @param tokenId token id
    /// @return current token nonce
    function nonces(uint256 tokenId) public view override returns (uint256) {
        require(_exists(tokenId), "!EXIST");
        return _nonces[tokenId];
    }

    /// @notice function to be called by anyone to approve `spender` using a Permit signature
    /// @dev Anyone can call this to approve `spender`, even a third-party
    /// @param spender_ the actor to approve
    /// @param tokenId_ the token id
    /// @param deadline_ the deadline for the permit to be used
    /// @param signature_ permit
    function permit(address spender_, uint256 tokenId_, uint256 deadline_, bytes memory signature_) external override {
        require(deadline_ >= block.timestamp, "EXPRIED");

        bytes32 digest = _buildDigest(spender_, tokenId_, _nonces[tokenId_], deadline_);

        (address recoveredAddress, ) = ECDSA.tryRecover(digest, signature_);
        require((recoveredAddress != address(0) && _isApprovedOrOwner(recoveredAddress, tokenId_)), "!PERMIT");

        _approve(spender_, tokenId_);
    }

    /// @notice Builds the permit digest to sign
    /// @param spender_ the token spender
    /// @param tokenId_ the tokenId
    /// @param nonce_ the nonce to make a permit for
    /// @param deadline_ the deadline before when the permit can be used
    /// @return the digest (following eip712) to sign
    function _buildDigest(
        address spender_,
        uint256 tokenId_,
        uint256 nonce_,
        uint256 deadline_
    ) private view returns (bytes32) {
        bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, spender_, tokenId_, nonce_, deadline_));
        return _hashTypedData(structHash);
    }

    /// @dev helper to easily increment a nonce for a given tokenId
    /// @param tokenId the tokenId to increment the nonce for
    function _incrementNonce(uint256 tokenId) internal {
        assembly {
            mstore(0x00, tokenId)
            mstore(0x20, _nonces.slot)
            let key := keccak256(0x00, 0x40)
            sstore(key, add(sload(key), 1))
        }
    }

    function _transfer(address from_, address to_, uint256 tokenId_) internal virtual override {
        // increment the nonce to be sure it can't be reused
        _incrementNonce(tokenId_);

        // do normal transfer
        super._transfer(from_, to_, tokenId_);
    }
}

/**
 * @dev Interface of IERC721URIStorage.
 */
interface IERC721URIStorage {
    event NewBaseTokenURI(string baseTokenURI);

    function baseURI() external view returns (string memory);
}

/**
 * @dev ERC721 token with storage based token URI management.
 */
abstract contract ERC721URIStorage is IERC721URIStorage, ERC721 {
    string internal _baseUri;

    function baseURI() external view override returns (string memory) {
        return _baseURI();
    }

    function _baseURI() internal view virtual override returns (string memory) {
        return _baseUri;
    }

    function _setBaseURI(string memory baseUri_) internal virtual {
        _baseUri = baseUri_;
        emit NewBaseTokenURI(baseUri_);
    }
}

interface IPresale {
    function setMinted(address account_, uint256 quantity_) external;
}

abstract contract ReentrancyGuard {
    error ReentrancyGuard__Locked();
    uint256 private locked = 1;

    modifier nonReentrant() virtual {
        if (locked > 1) revert ReentrancyGuard__Locked();

        locked = 2;

        _;

        locked = 1;
    }
}

library SafeTransferLib {
    /*//////////////////////////////////////////////////////////////
                             ETH OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferETH(address to, uint256 amount) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Transfer the ETH and store if it succeeded or not.
            success := call(gas(), to, amount, 0, 0, 0, 0)
        }

        require(success, "ETH_TRANSFER_FAILED");
    }

    /*//////////////////////////////////////////////////////////////
                            ERC20 OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferFrom(address token, address from, address to, uint256 amount) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), and(from, 0xffffffffffffffffffffffffffffffffffffffff)) // Append and mask the "from" argument.
            mstore(add(freeMemoryPointer, 36), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Append and mask the "to" argument.
            mstore(add(freeMemoryPointer, 68), amount) // Append the "amount" argument. Masking not required as it's a full 32 byte type.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 100 because the length of our calldata totals up like so: 4 + 32 * 3.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 100, 0, 32)
            )
        }

        require(success, "TRANSFER_FROM_FAILED");
    }

    function safeTransfer(address token, address to, uint256 amount) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Append and mask the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument. Masking not required as it's a full 32 byte type.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "TRANSFER_FAILED");
    }

    function safeApprove(address token, address to, uint256 amount) internal {
        bool success;

        /// @solidity memory-safe-assembly
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x095ea7b300000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Append and mask the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument. Masking not required as it's a full 32 byte type.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "APPROVE_FAILED");
    }
}

contract ETH20AVATAR is ERC721, ERC721Burnable, ERC721Permit, ERC721URIStorage, Ownable, ReentrancyGuard {
    uint256 public constant MAX_SUPLLY = 10000;
    uint256 private _idCounter;
    address public presaleContract;

    /**
     * @dev Initializes the MyBoi NFT.
     * @param name_ The name of the token.
     * @param symbol_ The symbol of the token.
     * @param baseUri_ The base URI for token metadata.
     */
    constructor(
        address presaleContract_,
        string memory name_,
        string memory symbol_,
        string memory baseUri_
    ) ERC721(name_, symbol_) {
        _setBaseURI(baseUri_);
        _idCounter = 1;
        presaleContract = presaleContract_;
    }

    /**
     * @dev Checks if a given token ID exists.
     * @param tokenId_ The ID of the token to check.
     * @return A boolean indicating whether the token exists.
     */
    function exists(uint256 tokenId_) external view returns (bool) {
        return _exists(tokenId_);
    }

    /**
     * @dev Returns the total number of tokens minted.
     * @return The total number of tokens minted.
     */
    function totalMinted() external view returns (uint256) {
        return _idCounter - 1;
    }

    /**
     * @dev Sets the base token URI for token metadata.
     * @param baseTokenURI_ The new base token URI.
     */
    function setBaseTokenURI(string calldata baseTokenURI_) external onlyOwner {
        _setBaseURI(baseTokenURI_);
    }

    function batchMint(uint256 quantity) external nonReentrant {
        address sender = _msgSender();
        IPresale(presaleContract).setMinted(sender, quantity);
        uint256 tokenId = _idCounter;

        for (uint i = 0; i < quantity; ) {
            _safeMint(sender, tokenId);
            unchecked {
                ++tokenId;
                ++i;
            }
        }
        _idCounter = tokenId;
    }

    // The following functions are overrides required by Solidity.

    /**
     * @dev Transfers the ownership of a token from one address to another.
     * @param from_ The current owner of the token.
     * @param to_ The new owner of the token.
     * @param tokenId_ The ID of the token to transfer.
     */
    function _transfer(address from_, address to_, uint256 tokenId_) internal override(ERC721, ERC721Permit) {
        super._transfer(from_, to_, tokenId_);
    }

    /**
     * @dev Returns the base URI for token metadata.
     * @return The base URI for token metadata.
     */
    function _baseURI() internal view virtual override(ERC721, ERC721URIStorage) returns (string memory) {
        return _baseUri;
    }

    /**
     * @dev Returns the name and version of the ERC712.
     * @return The name and version of the contract.
     */
    function _domainNameAndVersion() internal pure override returns (string memory, string memory) {
        return ("ETH20 AVATAR", "1");
    }
}

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