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