#[non_exhaustive]pub enum EmvMajorKeyDerivationMode {
EmvOptionA,
EmvOptionB,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against EmvMajorKeyDerivationMode
, 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 emvmajorkeyderivationmode = unimplemented!();
match emvmajorkeyderivationmode {
EmvMajorKeyDerivationMode::EmvOptionA => { /* ... */ },
EmvMajorKeyDerivationMode::EmvOptionB => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when emvmajorkeyderivationmode
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant EmvMajorKeyDerivationMode::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
EmvMajorKeyDerivationMode::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 EmvMajorKeyDerivationMode::NewFeature
is defined.
Specifically, when emvmajorkeyderivationmode
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on EmvMajorKeyDerivationMode::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 EmvMajorKeyDerivationMode
impl EmvMajorKeyDerivationMode
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 EmvMajorKeyDerivationMode
impl AsRef<str> for EmvMajorKeyDerivationMode
source§impl Clone for EmvMajorKeyDerivationMode
impl Clone for EmvMajorKeyDerivationMode
source§fn clone(&self) -> EmvMajorKeyDerivationMode
fn clone(&self) -> EmvMajorKeyDerivationMode
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for EmvMajorKeyDerivationMode
impl Debug for EmvMajorKeyDerivationMode
source§impl Display for EmvMajorKeyDerivationMode
impl Display for EmvMajorKeyDerivationMode
source§impl From<&str> for EmvMajorKeyDerivationMode
impl From<&str> for EmvMajorKeyDerivationMode
source§impl FromStr for EmvMajorKeyDerivationMode
impl FromStr for EmvMajorKeyDerivationMode
source§impl Hash for EmvMajorKeyDerivationMode
impl Hash for EmvMajorKeyDerivationMode
source§impl Ord for EmvMajorKeyDerivationMode
impl Ord for EmvMajorKeyDerivationMode
source§fn cmp(&self, other: &EmvMajorKeyDerivationMode) -> Ordering
fn cmp(&self, other: &EmvMajorKeyDerivationMode) -> 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 EmvMajorKeyDerivationMode
impl PartialEq for EmvMajorKeyDerivationMode
source§fn eq(&self, other: &EmvMajorKeyDerivationMode) -> bool
fn eq(&self, other: &EmvMajorKeyDerivationMode) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for EmvMajorKeyDerivationMode
impl PartialOrd for EmvMajorKeyDerivationMode
source§fn partial_cmp(&self, other: &EmvMajorKeyDerivationMode) -> Option<Ordering>
fn partial_cmp(&self, other: &EmvMajorKeyDerivationMode) -> 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 EmvMajorKeyDerivationMode
impl StructuralPartialEq for EmvMajorKeyDerivationMode
Auto Trait Implementations§
impl Freeze for EmvMajorKeyDerivationMode
impl RefUnwindSafe for EmvMajorKeyDerivationMode
impl Send for EmvMajorKeyDerivationMode
impl Sync for EmvMajorKeyDerivationMode
impl Unpin for EmvMajorKeyDerivationMode
impl UnwindSafe for EmvMajorKeyDerivationMode
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
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more