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