LibERC20Compat.sol

// SPDX-License-Identifier: Beta Software
pragma solidity ^0.8;

import "../tokens/IERC20.sol";

// Compatibility helpers for ERC20s.
library LibERC20Compat {
    error NotATokenError(IERC20 token);
    error TokenTransferFailedError(IERC20 token, address to, uint256 amount);

    // Perform an `IERC20.transfer()` handling non-compliant implementations.
    function compatTransfer(IERC20 token, address to, uint256 amount)
        internal
    {
        (bool s, bytes memory r) =
            address(token).call(abi.encodeCall(IERC20.transfer, (to, amount)));
        if (s) {
            if (r.length == 0) {
                uint256 cs;
                assembly { cs := extcodesize(token) }
                if (cs == 0) {
                    revert NotATokenError(token);
                }
                return;
            }
            if (abi.decode(r, (bool))) {
                return;
            }
        }
        revert TokenTransferFailedError(token, to, amount);
    }
}