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