// File: contracts/BD.sol




// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/// @title: BrainDigs
/// @author: manifold.xyz

import "./ERC721Creator.sol";

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                                                                                                                          //
//                                                                                                                                          //
//    ddoddxxkkkkkkkxxxxxxxxxxxxkkkxddddxddoodlclxkxddxxxddkOOkkkkoclllllllldkddo:::cx000000Oo::ccccoOKKKK00KKKK0K000OkkxxxxddddkOOkdllo    //
//    ddddddddxxxxxxxxxxxxxxkxxxxdoddddxxxddollc:cxkxddxxxddkOOkxollooooolllodoodc::oOOO0OOkdlc:cc:lk0KK0KK0KKKKK000OOOOOkkxxxxkOOkxdddl    //
//    ddddddoooodxxxxxxkkkkkkkxxdllldxkkkkkxoc:::;:oxxddxkxodOOxolllodoooollooclol:cxkdxxdddddllc:lk0K00KKKKKKKK00OOOOOOkkkkkO00Oxoooooc    //
//    ddddoooooooooddxxkkkkkxxdooodddxxkkkkOkoc::;;:clooodxxodkdooooodddoooloolclc:ldddddddxxdddodkKK00KKKKKKK00OOOOOOOOkkkO000Okxdoc:;:    //
//    xxxddooooooooooddxxxxxkxdddxxxxxxxkkOOOOxlclllc:clcccoocloollllllcllc:locclc:lddddddxxxdddxk0K0KKKKKKKK0OOOOOOOOkkkO0K0Okxxxdl::;;    //
//    kkkxxxddooooooooooolodxxxkkkkkxxxxxkkkkkxodddlc:;,,,:cc:;;clcc::::::;;:c:::ccllooddddddddxk0KKKKKKKKK0OOOOOOOOOkkO0K0Okdxxxocc::::    //
//    kkkkkkxxxxddddoooolcclooxkkkkxxkkkkxxxkOxoolllc'    .;c::::ccccc:::cccllcc:cc:cccccclldxxk0KKKKKKK0OxxkOOOOOkkO00KKOxolllxOkdccccc    //
//    dxxxkkkkkkxxxxxddolcllllllloddxkkkxxdodxolllcc:.     ,clc::::ccloodxdxxlcc,;cllllc::::cloxkkOOOOkxoloodxxxxxk0KKKOxocclcoOKklccccc    //
//    loodxxxxkkkkxkkxdooooolc:;;;::clloollccclccccc;.    .,clcc:::coxxxxkkkkxo:,,codxxdocclolllclodxxoc:cllooodk0KKKOxocccldoooolcccccc    //
//    llllooodxkxxxkkxdxxkkxolc:;;,;:ccllloolllc::cc,     .;ldol:::okxdxxxxkkklc;'cdkxkkkdllloooolooodxollllldk0KKKOxolccccllllccccclllo    //
//    lcloll::codxxxxxxxkkOkkkxdoc::cllllllllc::ccll;     .;lxkxl::ldoodxxxkkdll;.;oxkkkOxlclooooooollodooodk0KK0OxolccccclllooddxxkOO00    //
//    oooolc:;;;coooodxkkOOkkkkkkdc:lllllll:;,;:cccl,     .:oxxxddddoooddxxkxxdo,.,lxxxxdllllllllloolllllok0K00OxolllllodxkkOO0KKKKKKKKK    //
//    ddolc:c:;;colllodxxkkkkkkkkxxollllcc:;;;;;:cll,     .:oxxxdddddodxxdddodxd;..cdxdoodxdoxdlccllccclllxkOkxdoodxkOO0KKKKKKKKKKKKKKKK    //
//    ollccllllddooddddddoooddxxxkkdlllccccc::::lddo,     .cdkxddddxxdxxxxkkkkOkc .:oddoooodxxxdl::cllolcccloxkOO000KKKKKKXXXXXXXXXXXKKK    //
//    llllooddxddooooooooollccccloddollcccllllc:ldxd'     'codxxxxkkkkkkkkOOkkkOc .;okdoodxxxxxxdlclllccccccloxOKKKKKKKXXXXXXXXXXKKKKKKK    //
//    xxxxxxxxxddddxdxkxdxdddooooolcccc:c::ccccccoxd'    .;lddolcccccloodxOOkkkk: .,lxOOkkkkkxxxoc:::cccloolllook0KKKK00000000000OOOOOOO    //
//    ddddddxddddxxxkOOkkOOkxxxxolcc::ccc::::;c:codo'     ....         ...';:ldx,  ,lxkOkkkOOxoooolccclllooolloloddddooooddxxkkkOOOOOOOO    //
//    ooooooooooododdolllllccllc;;::cllllccccllcldxd'                         ...  ,ldkOOkOOkxxkOkxdol::cclllllllcccllllodxkkkOOOOOOOOO0    //
//    oooooolloooodxdlccc:,,;:c;::ccllllc:coooodxdc'.        ....',,,,,,'...       ,cxOOOOOOOOO0000Oxl;;ccccccllcc::cllllodxxkkkOOOOOOOO    //
//    ooooooloddddxdollc:;,;;:;::cllllc:::cllodxo,        .';coodxxdxxxkkxdoc;.    ',:dOOkO0OOKK0KKK0x:;:::clloolcccodxxkkOOO000000000KK    //
//    dooooodxxxkkxxxxdolcc::;:c:cllllc::;,,lxo;.      ..;coxkxxxxxkkxxkxxkkOOd'   '..'cxk0K0kO0kOO0KOdlcccclllllodxkO0KKXXXKXXXXXXXXXXX    //
//    oodoodxkkkkkkkkOkxxxxdolccllllllllc:::ll'      ....;lxkkdxkdc:;,'...',:ll.   '.  .:dO0OkdddxooxxdxxdolcclcldkkkOkOKKXXXXXXXXXXXXXX    //
//    oxxddxxkkkkkOOOOkxxkxxxdllllllllllllll:.      .'. .;ldddoc,.            ..   ,,   .:x00kddOK0dldddxxxdollodxxkkkkxk0KKKKKKKKXXXXXX    //
//    ;cccloodxxxkkkkkxdxkxdxdxxxxdollcclll:.     .,,.  .:ldo:.                 ...,c,   'lkKKOkkkOOkxxxxxxxxdlccoxkxkkOOkOKKKKKKKKKKKXX    //
//    ,'',,;:cloddxkkkxxkkxxdxkOOkdlcllllol'     .,l:.  .:ol'    ..,;:ccc:'      .',ld,  .;oOK00000K0xodxxxxxxdlccdkxxkOOOkOKKKXXXXXXXKK    //
//    :;;cloxkkOOOOOOOkkkkxxdxkxdolllllllc,.     'cdc.  .cc.   .;ldddxkkkkx;     .',lko.  'lk0K000K0koodxxxxxxxdlclxkxkOOOOkO0KKXXXXXXXX    //
//    dddxkOOOOOOOOOOkxxxdolcccccllcllllc:'     .:odc.  'c,  .,cdxkxxkkxxxxxo'  ...'cxx,  .:okO0KK00xodxxxkkkkkxo:;:cccldxxdxk0KXXXXXXXX    //
//    OkxkkOOOOkkkkkxdddooolcc:::clcllllllc'....:ldxl.  ,:.  'cdOkxxxkO0Okkkkc     'lk0o.  ,lxkxOOkxdddddxkkkkkkd:,;;;;;:ccllldkO000KKKK    //
//    kxxxkkkxxxxxxxdddddolccccccllllllolccccclllldko. .,c' .,ldOOkkkkkkkOOkx,     ,lx0k'  'cdkkxddxxxxxxxxxxxkxdc;:;:::ccllooodkOOOOOOO    //
//    xddxxxxxxxxxxxdddddolodxxxkxddddolcloooooccldxo. .;l; .,ldxkxkOkkxxkkko.     ,lk0k,  'lxOxdoloooddxxxxdodxxo:;;;:;:ccclooodkOO0000    //
//    dodxxxxxxxxxxxxxxkxddxkkkkkkxkxxo:clooollc;cdkl. .:ll' 'cdxdxxkOkkOOkkc.    .;okKO,  ,lOKOxddoolclloxxdodO00kdllccccclllodoxOOOO00    //
//    oodxkkxkkkkOOOkkkkxodxkkkxdolc:ccccllllc:::;:oc. .:ldl..,oxxkkkkkkkkkk:     .;ldxl. .;dOOxddxxddolc::;;::lxO0OkxxxxxdddoodddkOOOOO    //
//    dxxkOOkkOOOOOOkxxxoclolcc:::::lddlc:ccc::c:::l:. 'cllxd,.;oxkkOOxddxxd;     .:loc'  ,cdxollooodxddoc,''...':odooodxkkkkkxxxxkO0000    //
//    xxkOOkkxdkkxddollc,',::clllodxxolllcccccccllll:. ,cooodoc,,:oxOko:lxdx:     .:ll,  ':lollodooloolcccloc;'..',;:;;;:cooooddxxxOKKKK    //
//    ::cclccccll:ccc::;'.,cclodxkOkocloollllllllllo:..;ldolllddocclodl:cldOx;.  .,cc,  ':odollxxllcc:::::oxddc'.',,;:,,;;;;;ccc::;cdxkO    //
//    :ccllc:cddoolc:;;:,.,ldxkkkxdc;:cllllllllllllo:..:loolccccloddolcccoxkOOxoool:. .,cldxdlllllc:::c:;cxkkkdc;,,:cc;,;;;,;lolc:;;coll    //
//    lllllc:coodddxxodd:;lx0Okxoc;,,;;:cllllllllodd:..clolcccc:::clolcccooddddddd:. .;lollooollllcccc:::lxkOkxxxxolll:,;;;;;cdlcc;;coll    //
//    lllolc::;;;:cddoodddxkOkdl:;,,,,;:lddddxxxxxxd,.,clllllllcclloolcclooollcc:...,cooc;,:lolccllcc::;:dkkO000OOOxdll:,;:::cdocc:;:lcl    //
//    lololc:;;;;;:::ldkkxooooolc:;;;cdkkkOOkkkxxxxo'.;clloollcloololcclooooll:'..,codo:,,',colcccllc:;;;lk000000OOOOkdl:;;clldxol:;:ccc    //
//    oolllc:;;;;;codkkkkxlclllolclodxxkkkkkkkxxddxd,.:clooollloolllcclooool;...;cloooc,,,,,;coooccc:;,;::lk0000000OOOOko::lxxxxdlc;:ccc    //
//    oololc:;;;:lxOOkxdxxolloooddxkxxxxxxxdddxdodOx,':ccccllloooolllllcc;,..';cclllclo;,,,,,,cdxxdl:::::::cx00000000OOOOdodkkxxdol:cccc    //
//    oolllc:::ldOOOkxdddddoloodkOOkkkkxdolllllldkOd,;lllc::::;;;;,,,,,''',;:clcclccldko;,,,,,,:okOOxlc:::cccdO000OOOOOOOOxxkkxxddocclll    //
//    oolll::cdOOkkxxdddddxdddxkkkOOOkkxdllll::okOOo;:ccclllllclll:clooolccccllcclllxkkd:',;;;;;cdO0Okoccclllldk00OOOkkkOOxdxxkkxxdololl    //
//    :cccccdkOkkxxxddddddxkOkkkkkkkkxxddoooocoxxxo;;::,,,;:lodxxolldkkkxdlcllcccldxkkxxl,;:c:c:::ok00OdllloodddxOKK0OkxOOkdddddxxkkxoll    //
//    c;,:okOOkxxxxdxddddxOOOOOkkkxdoloooooodxkkxo:;;:;''';lxxxxdoooxkkkkkxlc:;;;lxkkkxxd:;ccccc:::cxO0OxooddxxdoxO00OkxO0Oxdddxxxxxddoo    //
//    cclxOOkkxxxxxxdddxkOOOO0OOkkdl::clloooxkOkdll::::;;cdkkkkxdoddkOkkkkxoc;,,,:xkxxxxxocldxodxoc;:dO0OkxdxxxxdddxkkkOO0Okxddxxxdooooo    //
//    oxkxxxxxxxxdxxxxkkkkO0OOkkxl:;;;;;;:coxkxolllccc::lkOkkkxdllodkkxxddxxl;,,,:dkxxxkkxlx00xoxkkl;:oO0OkxxkkkxxdddkO000OOOxdxkkkkkkOk    //
//    kOxddxxxxxddxxkkkkkkOOkxdoc:;,,,;;,;lxkdoooollolcokOkkkxdocclxOOkxxxkxl;,,;cdxkkOOkkoldko::cloo::ok00OkxxdxkkkkkkO00OOOkdxkkkOOkdl    //
//    Okxdodxxxdddxkkkkkkkxxddollol:,,;;;lkkkdoodddoolokOkxkkxdolc:dkkkkkkkxl;;;:cdkOOOOkkdcclc:;;:cdo;:dO0OxxxdodkkkkxkOOO0OxxO0OOkO0Od    //
//                                                                                                                                          //
//                                                                                                                                          //
//                                                                                                                                          //
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////


contract BD is ERC721Creator {
    constructor() ERC721Creator("BrainDigs", "BD") {}
}

// File: contracts/ERC721Creator.sol




// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/// @author: manifold.xyz

import "@openzeppelin/contracts/proxy/Proxy.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/StorageSlot.sol";

contract ERC721Creator is Proxy {
    
    constructor(string memory name, string memory symbol) {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = 0xe4E4003afE3765Aca8149a82fc064C0b125B9e5a;
        Address.functionDelegateCall(
            0xe4E4003afE3765Aca8149a82fc064C0b125B9e5a,
            abi.encodeWithSignature("initialize(string,string)", name, symbol)
        );
    }
        
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Returns the current implementation address.
     */
     function implementation() public view returns (address) {
        return _implementation();
    }

    function _implementation() internal override view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }    

}

// File: node_modules/@openzeppelin/contracts/proxy/Proxy.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)

pragma solidity ^0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 {
                revert(0, returndatasize())
            }
            default {
                return(0, returndatasize())
            }
        }
    }

    /**
     * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internal call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback() external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive() external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overridden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {}
}

// File: node_modules/@openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal 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
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: node_modules/@openzeppelin/contracts/utils/StorageSlot.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)

pragma solidity ^0.8.0;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }
}