閃貸如何保證借來的乙太幣/代幣會得到償還？

我想知道契約如何確保償還借款？誰能提供一個例子？

這一切都在一個功能中完成，所以如果錢沒有還清，你可以恢復。（例如，我寄給您 100 美元，您可以隨心所欲地使用它，但如果它在區塊結束時沒有回到我的手中，則 txn 會恢復）。這是標準：

function flashLoan(
   IERC3156FlashBorrower receiver,
   address token,
   uint256 amount,
   bytes calldata data
) external override returns (bool) {
   require(token == address(this), "FlashMinter: Unsupported currency");

   uint256 fee = flashFee(token, amount);
   _mint(address(receiver), amount);

   bytes32 CALLBACK_SUCCESS = keccak256("ERC3156FlashBorrower.onFlashLoan");
   require(
       receiver.onFlashLoan(msg.sender, token, amount, fee, data) == CALLBACK_SUCCESS,
       "FlashMinter: Callback failed"
   );

   uint256 _allowance = allowance(address(receiver), address(this));
   require(_allowance >= (amount + fee), "FlashMinter: Repay not approved");

   _approve(address(receiver), address(this), _allowance - (amount + fee));
   _burn(address(receiver), amount + fee);

  

來源：https ://soliditydeveloper.com/eip-3156

引用自：https://ethereum.stackexchange.com/questions/125476