// SPDX-License-Identifier: DOGE WORLDpragmasolidity ^0.8.0;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @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
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in// construction, since the code is only stored at the end of the// constructor execution.uint256 size;
// solhint-disable-next-line no-inline-assemblyassembly { size :=extcodesize(account) }
return size >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].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionCall(address target, bytesmemory data, stringmemory errorMessage) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value, stringmemory errorMessage) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory 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._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
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._
*/functionfunctionStaticCall(address target, bytesmemory data, stringmemory errorMessage) internalviewreturns (bytesmemory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory 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 v3.3._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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 v3.3._
*/functionfunctionDelegateCall(address target, bytesmemory data, stringmemory errorMessage) internalreturns (bytesmemory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function_verifyCallResult(bool success, bytesmemory returndata, stringmemory errorMessage) privatepurereturns(bytesmemory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly// solhint-disable-next-line no-inline-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: DOGE WORLDpragmasolidity ^0.8.0;import"./IERC20.sol";
import"./Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/librarySafeERC20{
usingAddressforaddress;
functionsafeTransfer(IERC20 token, address to, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
functionsafeTransferFrom(IERC20 token, addressfrom, address to, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/functionsafeApprove(IERC20 token, address spender, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/function_callOptionalReturn(IERC20 token, bytesmemory data) private{
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that// the target address contains contract code and also asserts for success in the low-level call.bytesmemory returndata =address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length>0) { // Return data is optional// solhint-disable-next-line max-line-lengthrequire(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}