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