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