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