Files
openzeppelin-contracts/contracts/AddressUtils.sol
John Shutt ad12381549 update constructor syntax for solidity 0.4.23 in numerous contracts (#921)
* update solidity-coverage to ^0.5.0

* update truffle dependency to ^4.1.8

* update solium to ^1.1.7

* update all contracts to solidity ^0.4.23
2018-05-08 18:02:00 -07:00

29 lines
1010 B
Solidity

pragma solidity ^0.4.23;
/**
* Utility library of inline functions on addresses
*/
library AddressUtils {
/**
* Returns whether the target address is a contract
* @dev This function will return false if invoked during the constructor of a contract,
* as the code is not actually created until after the constructor finishes.
* @param addr address to check
* @return whether the target address is a contract
*/
function isContract(address addr) internal view returns (bool) {
uint256 size;
// XXX Currently there is no better way to check if there is a contract in an address
// than to check the size of the code at that address.
// See https://ethereum.stackexchange.com/a/14016/36603
// for more details about how this works.
// TODO Check this again before the Serenity release, because all addresses will be
// contracts then.
assembly { size := extcodesize(addr) } // solium-disable-line security/no-inline-assembly
return size > 0;
}
}