#[non_exhaustive]pub enum MacAlgorithm {
Cmac,
HmacSha224,
HmacSha256,
HmacSha384,
HmacSha512,
Iso9797Algorithm1,
Iso9797Algorithm3,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against MacAlgorithm
, 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 macalgorithm = unimplemented!();
match macalgorithm {
MacAlgorithm::Cmac => { /* ... */ },
MacAlgorithm::HmacSha224 => { /* ... */ },
MacAlgorithm::HmacSha256 => { /* ... */ },
MacAlgorithm::HmacSha384 => { /* ... */ },
MacAlgorithm::HmacSha512 => { /* ... */ },
MacAlgorithm::Iso9797Algorithm1 => { /* ... */ },
MacAlgorithm::Iso9797Algorithm3 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when macalgorithm
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant MacAlgorithm::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
MacAlgorithm::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 MacAlgorithm::NewFeature
is defined.
Specifically, when macalgorithm
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on MacAlgorithm::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
Cmac
HmacSha224
HmacSha256
HmacSha384
HmacSha512
Iso9797Algorithm1
Iso9797Algorithm3
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for MacAlgorithm
impl AsRef<str> for MacAlgorithm
source§impl Clone for MacAlgorithm
impl Clone for MacAlgorithm
source§fn clone(&self) -> MacAlgorithm
fn clone(&self) -> MacAlgorithm
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for MacAlgorithm
impl Debug for MacAlgorithm
source§impl From<&str> for MacAlgorithm
impl From<&str> for MacAlgorithm
source§impl FromStr for MacAlgorithm
impl FromStr for MacAlgorithm
source§impl Hash for MacAlgorithm
impl Hash for MacAlgorithm
source§impl Ord for MacAlgorithm
impl Ord for MacAlgorithm
source§fn cmp(&self, other: &MacAlgorithm) -> Ordering
fn cmp(&self, other: &MacAlgorithm) -> 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 MacAlgorithm
impl PartialEq for MacAlgorithm
source§fn eq(&self, other: &MacAlgorithm) -> bool
fn eq(&self, other: &MacAlgorithm) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for MacAlgorithm
impl PartialOrd for MacAlgorithm
source§fn partial_cmp(&self, other: &MacAlgorithm) -> Option<Ordering>
fn partial_cmp(&self, other: &MacAlgorithm) -> 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 MacAlgorithm
impl StructuralEq for MacAlgorithm
impl StructuralPartialEq for MacAlgorithm
Auto Trait Implementations§
impl RefUnwindSafe for MacAlgorithm
impl Send for MacAlgorithm
impl Sync for MacAlgorithm
impl Unpin for MacAlgorithm
impl UnwindSafe for MacAlgorithm
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<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.