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