// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @notice Based on:
* https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol
* Requires EIP-1052.
* @dev Utility library of inline functions on addresses.
*/
library AddressUtils
{
/**
* @dev Returns whether the target address is a contract.
* @param _addr Address to check.
* @return addressCheck True if _addr is a contract, false if not.
*/
function isContract(
address _addr
)
internal
view
returns (bool addressCheck)
{
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
assembly { codehash := extcodehash(_addr) } // solhint-disable-line
addressCheck = (codehash != 0x0 && codehash != accountHash);
}
}
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