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