30 lines
1.5 KiB
Solidity
30 lines
1.5 KiB
Solidity
// SPDX-License-Identifier: GPL-3.0
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pragma solidity >=0.6.0;
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// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
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library TransferHelper {
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function safeApprove(address token, address to, uint value) internal {
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// bytes4(keccak256(bytes('approve(address,uint256)')));
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(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
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require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
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}
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function safeTransfer(address token, address to, uint value) internal {
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// bytes4(keccak256(bytes('transfer(address,uint256)')));
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(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
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require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
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}
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function safeTransferFrom(address token, address from, address to, uint value) internal {
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// bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
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(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
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require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
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}
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function safeTransferETH(address to, uint value) internal {
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(bool success,) = to.call{value:value}(new bytes(0));
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require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
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}
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}
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