#[non_exhaustive]pub enum ChannelMessagePersistenceType {
NonPersistent,
Persistent,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against ChannelMessagePersistenceType, 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 channelmessagepersistencetype = unimplemented!();
match channelmessagepersistencetype {
ChannelMessagePersistenceType::NonPersistent => { /* ... */ },
ChannelMessagePersistenceType::Persistent => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when channelmessagepersistencetype represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ChannelMessagePersistenceType::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
ChannelMessagePersistenceType::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 ChannelMessagePersistenceType::NewFeature is defined.
Specifically, when channelmessagepersistencetype represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on ChannelMessagePersistenceType::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
NonPersistent
Persistent
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 ChannelMessagePersistenceType
impl ChannelMessagePersistenceType
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 ChannelMessagePersistenceType
impl AsRef<str> for ChannelMessagePersistenceType
source§impl Clone for ChannelMessagePersistenceType
impl Clone for ChannelMessagePersistenceType
source§fn clone(&self) -> ChannelMessagePersistenceType
fn clone(&self) -> ChannelMessagePersistenceType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl From<&str> for ChannelMessagePersistenceType
impl From<&str> for ChannelMessagePersistenceType
source§impl Hash for ChannelMessagePersistenceType
impl Hash for ChannelMessagePersistenceType
source§impl Ord for ChannelMessagePersistenceType
impl Ord for ChannelMessagePersistenceType
source§fn cmp(&self, other: &ChannelMessagePersistenceType) -> Ordering
fn cmp(&self, other: &ChannelMessagePersistenceType) -> 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 ChannelMessagePersistenceType
impl PartialEq for ChannelMessagePersistenceType
source§fn eq(&self, other: &ChannelMessagePersistenceType) -> bool
fn eq(&self, other: &ChannelMessagePersistenceType) -> bool
self and other values to be equal, and is used
by ==.source§impl PartialOrd for ChannelMessagePersistenceType
impl PartialOrd for ChannelMessagePersistenceType
source§fn partial_cmp(&self, other: &ChannelMessagePersistenceType) -> Option<Ordering>
fn partial_cmp(&self, other: &ChannelMessagePersistenceType) -> 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 ChannelMessagePersistenceType
impl StructuralEq for ChannelMessagePersistenceType
impl StructuralPartialEq for ChannelMessagePersistenceType
Auto Trait Implementations§
impl RefUnwindSafe for ChannelMessagePersistenceType
impl Send for ChannelMessagePersistenceType
impl Sync for ChannelMessagePersistenceType
impl Unpin for ChannelMessagePersistenceType
impl UnwindSafe for ChannelMessagePersistenceType
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
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key and return true if they are equal.