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Unchecked return value detector#

Reports when a function call return value is unused.

Example#

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import "@openzeppelin/contracts/interfaces/IERC20.sol";

contract Treasury {
    function deposit(IERC20 token, uint256 amount) external {
        token.transferFrom(msg.sender, address(this), amount); // (1)!
    }

    function withdrawNative(address to, uint256 amount) external {
        to.call{value: amount}(""); // (2)!
    }

    function withdraw(IERC20 token, address to, uint256 amount) external {
        token.transfer(to, amount);  // (3)!
    }
}
  1. The return value of transferFrom is unused, possibly causing logic errors since the transfer may fail.
  2. The return value of call is unused, silently discarding the boolean indicating whether the call succeeded.
  3. The return value of transfer is unused, possibly causing logic errors since the transfer may fail.

Parameters#

The detector does not accept any additional parameters.