Enum aws_sdk_s3::types::SessionMode
source · #[non_exhaustive]pub enum SessionMode {
ReadOnly,
ReadWrite,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against SessionMode
, 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 sessionmode = unimplemented!();
match sessionmode {
SessionMode::ReadOnly => { /* ... */ },
SessionMode::ReadWrite => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when sessionmode
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant SessionMode::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
SessionMode::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 SessionMode::NewFeature
is defined.
Specifically, when sessionmode
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on SessionMode::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
ReadOnly
ReadWrite
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 SessionMode
impl SessionMode
source§impl SessionMode
impl SessionMode
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 SessionMode
impl AsRef<str> for SessionMode
source§impl Clone for SessionMode
impl Clone for SessionMode
source§fn clone(&self) -> SessionMode
fn clone(&self) -> SessionMode
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for SessionMode
impl Debug for SessionMode
source§impl Display for SessionMode
impl Display for SessionMode
source§impl From<&str> for SessionMode
impl From<&str> for SessionMode
source§impl FromStr for SessionMode
impl FromStr for SessionMode
source§impl Hash for SessionMode
impl Hash for SessionMode
source§impl Ord for SessionMode
impl Ord for SessionMode
source§fn cmp(&self, other: &SessionMode) -> Ordering
fn cmp(&self, other: &SessionMode) -> 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 SessionMode
impl PartialEq for SessionMode
source§impl PartialOrd for SessionMode
impl PartialOrd for SessionMode
impl Eq for SessionMode
impl StructuralPartialEq for SessionMode
Auto Trait Implementations§
impl Freeze for SessionMode
impl RefUnwindSafe for SessionMode
impl Send for SessionMode
impl Sync for SessionMode
impl Unpin for SessionMode
impl UnwindSafe for SessionMode
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)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.