5dfe7215a9
* Initial migration to Solidity 0.6.x - v3.0 first steps (#2063) * Initial migration, missing GSN, 721, 777 and Crowdsales. * Add _beforeTokenOperation and _afterTokenOperation. * Add documentation for hooks. * Add hooks doc * Add missing drafts * Add back ERC721 with hooks * Bring back ERC777 * Notes on hooks * Bring back GSN * Make functions virtual * Make GSN overrides explicit * Fix ERC20Pausable tests * Remove virtual from some view functions * Update linter * Delete examples * Remove unnecessary virtual * Remove roles from Pausable * Remove roles * Remove users of roles * Adapt ERC20 tests * Fix ERC721 tests * Add all ERC721 hooks * Add ERC777 hooks * Fix remaining tests * Bump compiler version * Move 721BurnableMock into mocks directory * Remove _before hooks * Fix tests * Upgrade linter * Put modifiers last * Remove _beforeTokenApproval and _beforeOperatorApproval hooks
71 lines
2.9 KiB
Solidity
71 lines
2.9 KiB
Solidity
pragma solidity ^0.6.0;
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/**
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* @dev Collection of functions related to the address type
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*/
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library Address {
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/**
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* @dev Returns true if `account` is a contract.
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*
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* [IMPORTANT]
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* ====
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* It is unsafe to assume that an address for which this function returns
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* false is an externally-owned account (EOA) and not a contract.
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*
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* Among others, `isContract` will return false for the following
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* types of addresses:
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*
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* - an externally-owned account
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* - a contract in construction
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* - an address where a contract will be created
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* - an address where a contract lived, but was destroyed
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* ====
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*/
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function isContract(address account) internal view returns (bool) {
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// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
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// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
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// for accounts without code, i.e. `keccak256('')`
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bytes32 codehash;
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bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
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// solhint-disable-next-line no-inline-assembly
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assembly { codehash := extcodehash(account) }
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return (codehash != accountHash && codehash != 0x0);
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}
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/**
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* @dev Converts an `address` into `address payable`. Note that this is
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* simply a type cast: the actual underlying value is not changed.
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*
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* _Available since v2.4.0._
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*/
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function toPayable(address account) internal pure returns (address payable) {
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return address(uint160(account));
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}
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/**
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* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
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* `recipient`, forwarding all available gas and reverting on errors.
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*
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* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
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* of certain opcodes, possibly making contracts go over the 2300 gas limit
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* imposed by `transfer`, making them unable to receive funds via
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* `transfer`. {sendValue} removes this limitation.
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*
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* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
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*
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* IMPORTANT: because control is transferred to `recipient`, care must be
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* taken to not create reentrancy vulnerabilities. Consider using
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* {ReentrancyGuard} or the
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* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
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*
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* _Available since v2.4.0._
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*/
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function sendValue(address payable recipient, uint256 amount) internal {
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require(address(this).balance >= amount, "Address: insufficient balance");
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// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
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(bool success, ) = recipient.call.value(amount)("");
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require(success, "Address: unable to send value, recipient may have reverted");
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}
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}
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