solidity/test/libsolidity/syntaxTests/underscore/in_function.sol

contract C {
    function f() public pure returns (uint) {
        uint _;
        return _;
    }

    function g() public pure returns (uint) {
        uint _ = 1;
        return _;
    }

    function h() public pure {
        _;
    }
}
// ----
// DeclarationError 7576: (230-231): Undeclared identifier.