#[non_exhaustive]pub enum MajorKeyDerivationMode {
EmvOptionA,
EmvOptionB,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against MajorKeyDerivationMode
, 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 majorkeyderivationmode = unimplemented!();
match majorkeyderivationmode {
MajorKeyDerivationMode::EmvOptionA => { /* ... */ },
MajorKeyDerivationMode::EmvOptionB => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when majorkeyderivationmode
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant MajorKeyDerivationMode::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
MajorKeyDerivationMode::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 MajorKeyDerivationMode::NewFeature
is defined.
Specifically, when majorkeyderivationmode
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on MajorKeyDerivationMode::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
EmvOptionA
EmvOptionB
Unknown(UnknownVariantValue)
Unknown
. See the docs on this enum for the correct way to handle unknown variants.Unknown
contains new variants that have been added since this code was generated.
Implementations§
source§impl MajorKeyDerivationMode
impl MajorKeyDerivationMode
sourcepub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
pub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
Parses the enum value while disallowing unknown variants.
Unknown variants will result in an error.
Trait Implementations§
source§impl AsRef<str> for MajorKeyDerivationMode
impl AsRef<str> for MajorKeyDerivationMode
source§impl Clone for MajorKeyDerivationMode
impl Clone for MajorKeyDerivationMode
source§fn clone(&self) -> MajorKeyDerivationMode
fn clone(&self) -> MajorKeyDerivationMode
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for MajorKeyDerivationMode
impl Debug for MajorKeyDerivationMode
source§impl From<&str> for MajorKeyDerivationMode
impl From<&str> for MajorKeyDerivationMode
source§impl FromStr for MajorKeyDerivationMode
impl FromStr for MajorKeyDerivationMode
source§impl Hash for MajorKeyDerivationMode
impl Hash for MajorKeyDerivationMode
source§impl Ord for MajorKeyDerivationMode
impl Ord for MajorKeyDerivationMode
source§fn cmp(&self, other: &MajorKeyDerivationMode) -> Ordering
fn cmp(&self, other: &MajorKeyDerivationMode) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for MajorKeyDerivationMode
impl PartialEq for MajorKeyDerivationMode
source§fn eq(&self, other: &MajorKeyDerivationMode) -> bool
fn eq(&self, other: &MajorKeyDerivationMode) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for MajorKeyDerivationMode
impl PartialOrd for MajorKeyDerivationMode
source§fn partial_cmp(&self, other: &MajorKeyDerivationMode) -> Option<Ordering>
fn partial_cmp(&self, other: &MajorKeyDerivationMode) -> 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 MajorKeyDerivationMode
impl StructuralEq for MajorKeyDerivationMode
impl StructuralPartialEq for MajorKeyDerivationMode
Auto Trait Implementations§
impl RefUnwindSafe for MajorKeyDerivationMode
impl Send for MajorKeyDerivationMode
impl Sync for MajorKeyDerivationMode
impl Unpin for MajorKeyDerivationMode
impl UnwindSafe for MajorKeyDerivationMode
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.