Enum aws_sdk_databrew::model::Source
source · #[non_exhaustive]
pub enum Source {
Datacatalog,
Database,
S3,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against Source
, 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 source = unimplemented!();
match source {
Source::Datacatalog => { /* ... */ },
Source::Database => { /* ... */ },
Source::S3 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when source
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant Source::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
Source::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 Source::NewFeature
is defined.
Specifically, when source
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on Source::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
Datacatalog
Database
S3
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl Ord for Source
impl Ord for Source
source§impl PartialEq<Source> for Source
impl PartialEq<Source> for Source
source§impl PartialOrd<Source> for Source
impl PartialOrd<Source> for Source
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 Source
impl StructuralEq for Source
impl StructuralPartialEq for Source
Auto Trait Implementations§
impl RefUnwindSafe for Source
impl Send for Source
impl Sync for Source
impl Unpin for Source
impl UnwindSafe for Source
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.