[][src]Trait sgx_tstd::marker::StructuralEq

#[lang = "structural_teq"]pub trait StructuralEq { }
🔬 This is a nightly-only experimental API. (structural_match)

Required trait for constants used in pattern matches.

Any type that derives Eq automatically implements this trait, regardless of whether its type-parameters implement Eq.

This is a hack to workaround a limitation in our type-system.

Background:

We want to require that types of consts used in pattern matches have the attribute #[derive(PartialEq, Eq)].

In a more ideal world, we could check that requirement by just checking that the given type implements both (1.) the StructuralPartialEq trait and (2.) the Eq trait. However, you can have ADTs that do derive(PartialEq, Eq), and be a case that we want the compiler to accept, and yet the constant's type fails to implement Eq.

Namely, a case like this:

#[derive(PartialEq, Eq)]
struct Wrap<X>(X);
fn higher_order(_: &()) { }
const CFN: Wrap<fn(&())> = Wrap(higher_order);
fn main() {
    match CFN {
        CFN => {}
        _ => {}
    }
}

(The problem in the above code is that Wrap<fn(&())> does not implement PartialEq, nor Eq, because for<'a> fn(&'a _) does not implement those traits.)

Therefore, we cannot rely on naive check for StructuralPartialEq and mere Eq.

As a hack to work around this, we use two separate traits injected by each of the two derives (#[derive(PartialEq)] and #[derive(Eq)]) and check that both of them are present as part of structural-match checking.

Implementations on Foreign Types

impl<'a> StructuralEq for Utf8LossyChunk<'a>[src]

impl StructuralEq for CpuidResult[src]

impl StructuralEq for IntErrorKind[src]

impl StructuralEq for CollectionAllocErr[src]

impl StructuralEq for AlighAllocErr[src]

impl StructuralEq for ProtectAttr[src]

impl StructuralEq for RsrvMemAllocErr[src]

impl StructuralEq for AlignLayoutErr[src]

impl StructuralEq for AlignReq[src]

impl StructuralEq for dir_index_t[src]

impl StructuralEq for sgx_exception_vector_t[src]

impl StructuralEq for sgx_quote3_error_t[src]

impl StructuralEq for sgx_uswitchless_worker_event_t[src]

impl StructuralEq for sgx_ql_request_policy_t[src]

impl StructuralEq for sgx_quote_sign_type_t[src]

impl StructuralEq for sgx_rsa_result_t[src]

impl StructuralEq for sgx_uswitchless_worker_type_t[src]

impl StructuralEq for sgx_device_status_t[src]

impl StructuralEq for sgx_ql_cert_key_type_t[src]

impl StructuralEq for sgx_ql_path_type_t[src]

impl StructuralEq for sgx_rsa_key_type_t[src]

impl StructuralEq for sgx_ra_key_type_t[src]

impl StructuralEq for sgx_pce_error_t[src]

impl StructuralEq for sgx_qcnl_error_t[src]

impl StructuralEq for sgx_status_t[src]

impl StructuralEq for sgx_ql_attestation_algorithm_id_t[src]

impl StructuralEq for sgx_ql_qv_result_t[src]

impl StructuralEq for sgx_generic_ecresult_t[src]

impl StructuralEq for sgx_ql_config_version_t[src]

impl StructuralEq for sgx_dh_session_role_t[src]

impl StructuralEq for sgx_qv_path_type_t[src]

impl StructuralEq for sgx_exception_type_t[src]

impl StructuralEq for Feature[src]

impl StructuralEq for SeekFrom[src]

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Implementors

impl StructuralEq for AllocInit[src]

impl StructuralEq for ReallocPlacement[src]

impl StructuralEq for TryReserveError[src]

impl StructuralEq for VarError[src]

impl StructuralEq for ErrorKind[src]

impl StructuralEq for sgx_tstd::io::SeekFrom[src]

impl StructuralEq for IpAddr[src]

impl StructuralEq for Ipv6MulticastScope[src]

impl StructuralEq for Shutdown[src]

impl StructuralEq for SocketAddr[src]

impl StructuralEq for FpCategory[src]

impl StructuralEq for SearchStep[src]

impl StructuralEq for Ordering[src]

impl StructuralEq for AllocErr[src]

impl StructuralEq for Layout[src]

impl StructuralEq for LayoutErr[src]

impl StructuralEq for TypeId[src]

impl StructuralEq for CharTryFromError[src]

impl StructuralEq for DecodeUtf16Error[src]

impl StructuralEq for ParseCharError[src]

impl StructuralEq for UnicodeVersion[src]

impl StructuralEq for CString[src]

impl StructuralEq for FromBytesWithNulError[src]

impl StructuralEq for IntoStringError[src]

impl StructuralEq for NulError[src]

impl StructuralEq for Error[src]

impl StructuralEq for PhantomPinned[src]

impl StructuralEq for AddrParseError[src]

impl StructuralEq for NonZeroI128[src]

impl StructuralEq for NonZeroI16[src]

impl StructuralEq for NonZeroI32[src]

impl StructuralEq for NonZeroI64[src]

impl StructuralEq for NonZeroI8[src]

impl StructuralEq for NonZeroIsize[src]

impl StructuralEq for NonZeroU128[src]

impl StructuralEq for NonZeroU16[src]

impl StructuralEq for NonZeroU32[src]

impl StructuralEq for NonZeroU64[src]

impl StructuralEq for NonZeroU8[src]

impl StructuralEq for NonZeroUsize[src]

impl StructuralEq for ParseFloatError[src]

impl StructuralEq for ParseIntError[src]

impl StructuralEq for TryFromIntError[src]

impl StructuralEq for RangeFull[src]

impl StructuralEq for NoneError[src]

impl StructuralEq for StripPrefixError[src]

impl StructuralEq for ParseBoolError[src]

impl StructuralEq for Utf8Error[src]

impl StructuralEq for FromUtf8Error[src]

impl StructuralEq for String[src]

impl StructuralEq for WaitTimeoutResult[src]

impl StructuralEq for ThreadId[src]

impl StructuralEq for Duration[src]

impl StructuralEq for Instant[src]

impl StructuralEq for SystemTime[src]

impl StructuralEq for FileType[src]

impl StructuralEq for Permissions[src]

impl<'a> StructuralEq for Component<'a>[src]

impl<'a> StructuralEq for Prefix<'a>[src]

impl<'a> StructuralEq for PrefixComponent<'a>[src]

impl<Idx> StructuralEq for Range<Idx>[src]

impl<Idx> StructuralEq for RangeFrom<Idx>[src]

impl<Idx> StructuralEq for RangeInclusive<Idx>[src]

impl<Idx> StructuralEq for RangeTo<Idx>[src]

impl<Idx> StructuralEq for RangeToInclusive<Idx>[src]

impl<T> StructuralEq for Bound<T>[src]

impl<T> StructuralEq for Option<T>[src]

impl<T> StructuralEq for Poll<T>[src]

impl<T> StructuralEq for Reverse<T>[src]

impl<T> StructuralEq for BTreeSet<T>[src]

impl<T> StructuralEq for Cursor<T>[src]

impl<T> StructuralEq for PhantomData<T> where
    T: ?Sized
[src]

impl<T> StructuralEq for ManuallyDrop<T> where
    T: ?Sized
[src]

impl<T> StructuralEq for Wrapping<T>[src]

impl<T, E> StructuralEq for Result<T, E>[src]

impl<Y, R> StructuralEq for GeneratorState<Y, R>[src]

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