#[non_exhaustive]pub enum ResourceAttribute {
CreationPolicy,
DeletionPolicy,
Metadata,
Properties,
Tags,
UpdatePolicy,
UpdateReplacePolicy,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ResourceAttribute
, 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 resourceattribute = unimplemented!();
match resourceattribute {
ResourceAttribute::CreationPolicy => { /* ... */ },
ResourceAttribute::DeletionPolicy => { /* ... */ },
ResourceAttribute::Metadata => { /* ... */ },
ResourceAttribute::Properties => { /* ... */ },
ResourceAttribute::Tags => { /* ... */ },
ResourceAttribute::UpdatePolicy => { /* ... */ },
ResourceAttribute::UpdateReplacePolicy => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when resourceattribute
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ResourceAttribute::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ResourceAttribute::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 ResourceAttribute::NewFeature
is defined.
Specifically, when resourceattribute
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ResourceAttribute::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
CreationPolicy
DeletionPolicy
Metadata
Properties
Tags
UpdatePolicy
UpdateReplacePolicy
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 ResourceAttribute
impl ResourceAttribute
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 ResourceAttribute
impl AsRef<str> for ResourceAttribute
source§impl Clone for ResourceAttribute
impl Clone for ResourceAttribute
source§fn clone(&self) -> ResourceAttribute
fn clone(&self) -> ResourceAttribute
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ResourceAttribute
impl Debug for ResourceAttribute
source§impl Display for ResourceAttribute
impl Display for ResourceAttribute
source§impl From<&str> for ResourceAttribute
impl From<&str> for ResourceAttribute
source§impl FromStr for ResourceAttribute
impl FromStr for ResourceAttribute
source§impl Hash for ResourceAttribute
impl Hash for ResourceAttribute
source§impl Ord for ResourceAttribute
impl Ord for ResourceAttribute
source§fn cmp(&self, other: &ResourceAttribute) -> Ordering
fn cmp(&self, other: &ResourceAttribute) -> 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 ResourceAttribute
impl PartialEq for ResourceAttribute
source§fn eq(&self, other: &ResourceAttribute) -> bool
fn eq(&self, other: &ResourceAttribute) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for ResourceAttribute
impl PartialOrd for ResourceAttribute
source§fn partial_cmp(&self, other: &ResourceAttribute) -> Option<Ordering>
fn partial_cmp(&self, other: &ResourceAttribute) -> 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 ResourceAttribute
impl StructuralPartialEq for ResourceAttribute
Auto Trait Implementations§
impl Freeze for ResourceAttribute
impl RefUnwindSafe for ResourceAttribute
impl Send for ResourceAttribute
impl Sync for ResourceAttribute
impl Unpin for ResourceAttribute
impl UnwindSafe for ResourceAttribute
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.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more