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