#[non_exhaustive]pub enum DbInstanceType {
DbInflux12Xlarge,
DbInflux16Xlarge,
DbInflux2Xlarge,
DbInflux4Xlarge,
DbInflux8Xlarge,
DbInfluxLarge,
DbInfluxMedium,
DbInfluxXlarge,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against DbInstanceType
, 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 dbinstancetype = unimplemented!();
match dbinstancetype {
DbInstanceType::DbInflux12Xlarge => { /* ... */ },
DbInstanceType::DbInflux16Xlarge => { /* ... */ },
DbInstanceType::DbInflux2Xlarge => { /* ... */ },
DbInstanceType::DbInflux4Xlarge => { /* ... */ },
DbInstanceType::DbInflux8Xlarge => { /* ... */ },
DbInstanceType::DbInfluxLarge => { /* ... */ },
DbInstanceType::DbInfluxMedium => { /* ... */ },
DbInstanceType::DbInfluxXlarge => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when dbinstancetype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant DbInstanceType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
DbInstanceType::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 DbInstanceType::NewFeature
is defined.
Specifically, when dbinstancetype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on DbInstanceType::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
DbInflux12Xlarge
DbInflux16Xlarge
DbInflux2Xlarge
DbInflux4Xlarge
DbInflux8Xlarge
DbInfluxLarge
DbInfluxMedium
DbInfluxXlarge
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 DbInstanceType
impl DbInstanceType
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 DbInstanceType
impl AsRef<str> for DbInstanceType
source§impl Clone for DbInstanceType
impl Clone for DbInstanceType
source§fn clone(&self) -> DbInstanceType
fn clone(&self) -> DbInstanceType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for DbInstanceType
impl Debug for DbInstanceType
source§impl Display for DbInstanceType
impl Display for DbInstanceType
source§impl From<&str> for DbInstanceType
impl From<&str> for DbInstanceType
source§impl FromStr for DbInstanceType
impl FromStr for DbInstanceType
source§impl Hash for DbInstanceType
impl Hash for DbInstanceType
source§impl Ord for DbInstanceType
impl Ord for DbInstanceType
source§fn cmp(&self, other: &DbInstanceType) -> Ordering
fn cmp(&self, other: &DbInstanceType) -> 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 DbInstanceType
impl PartialEq for DbInstanceType
source§fn eq(&self, other: &DbInstanceType) -> bool
fn eq(&self, other: &DbInstanceType) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for DbInstanceType
impl PartialOrd for DbInstanceType
source§fn partial_cmp(&self, other: &DbInstanceType) -> Option<Ordering>
fn partial_cmp(&self, other: &DbInstanceType) -> 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 DbInstanceType
impl StructuralPartialEq for DbInstanceType
Auto Trait Implementations§
impl Freeze for DbInstanceType
impl RefUnwindSafe for DbInstanceType
impl Send for DbInstanceType
impl Sync for DbInstanceType
impl Unpin for DbInstanceType
impl UnwindSafe for DbInstanceType
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> 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.