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