solidity/test/libsolidity/syntaxTests/specialFunctions/types_with_unspecified_encoding_structs.sol

contract C {
    struct S { uint x; }
    S s;
    struct T { uint y; }
    T t;
    function f() public view {
        bytes32 a = sha256(abi.encodePacked(s, t));
        a;
    }
}
// ----
// TypeError: (156-157): This type cannot be encoded.
// TypeError: (159-160): This type cannot be encoded.