#[non_exhaustive]
pub enum SignalDecoderType {
CanSignal,
ObdSignal,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against SignalDecoderType
, it is important to ensure
your code is forward-compatible. That is, if a match arm handles a case for a
feature that is supported by the service but has not been represented as an enum
variant in a current version of SDK, your code should continue to work when you
upgrade SDK to a future version in which the enum does include a variant for that
feature.
Here is an example of how you can make a match expression forward-compatible:
# let signaldecodertype = unimplemented!();
match signaldecodertype {
SignalDecoderType::CanSignal => { /* ... */ },
SignalDecoderType::ObdSignal => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when signaldecodertype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant SignalDecoderType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
SignalDecoderType::Unknown(UnknownVariantValue("NewFeature".to_owned()))
and calling as_str
on it yields "NewFeature"
.
This match expression is forward-compatible when executed with a newer
version of SDK where the variant SignalDecoderType::NewFeature
is defined.
Specifically, when signaldecodertype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on SignalDecoderType::NewFeature
also yielding "NewFeature"
.
Explicitly matching on the Unknown
variant should
be avoided for two reasons:
- The inner data
UnknownVariantValue
is opaque, and no further information can be extracted. - It might inadvertently shadow other intended match arms.
Variants (Non-exhaustive)§
This enum is marked as non-exhaustive
CanSignal
ObdSignal
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for SignalDecoderType
impl AsRef<str> for SignalDecoderType
source§impl Clone for SignalDecoderType
impl Clone for SignalDecoderType
source§fn clone(&self) -> SignalDecoderType
fn clone(&self) -> SignalDecoderType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for SignalDecoderType
impl Debug for SignalDecoderType
source§impl From<&str> for SignalDecoderType
impl From<&str> for SignalDecoderType
source§impl FromStr for SignalDecoderType
impl FromStr for SignalDecoderType
source§impl Hash for SignalDecoderType
impl Hash for SignalDecoderType
source§impl Ord for SignalDecoderType
impl Ord for SignalDecoderType
source§fn cmp(&self, other: &SignalDecoderType) -> Ordering
fn cmp(&self, other: &SignalDecoderType) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<SignalDecoderType> for SignalDecoderType
impl PartialEq<SignalDecoderType> for SignalDecoderType
source§fn eq(&self, other: &SignalDecoderType) -> bool
fn eq(&self, other: &SignalDecoderType) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<SignalDecoderType> for SignalDecoderType
impl PartialOrd<SignalDecoderType> for SignalDecoderType
source§fn partial_cmp(&self, other: &SignalDecoderType) -> Option<Ordering>
fn partial_cmp(&self, other: &SignalDecoderType) -> Option<Ordering>
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read moreimpl Eq for SignalDecoderType
impl StructuralEq for SignalDecoderType
impl StructuralPartialEq for SignalDecoderType
Auto Trait Implementations§
impl RefUnwindSafe for SignalDecoderType
impl Send for SignalDecoderType
impl Sync for SignalDecoderType
impl Unpin for SignalDecoderType
impl UnwindSafe for SignalDecoderType
Blanket Implementations§
source§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.