Enum bonsaidb::keystorage::s3::aws_sdk_s3::types::ExpressionType
#[non_exhaustive]pub enum ExpressionType {
Sql,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ExpressionType
, 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 expressiontype = unimplemented!();
match expressiontype {
ExpressionType::Sql => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when expressiontype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ExpressionType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ExpressionType::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 ExpressionType::NewFeature
is defined.
Specifically, when expressiontype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ExpressionType::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
Sql
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
§impl AsRef<str> for ExpressionType
impl AsRef<str> for ExpressionType
§impl Clone for ExpressionType
impl Clone for ExpressionType
§fn clone(&self) -> ExpressionType
fn clone(&self) -> ExpressionType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read more§impl Debug for ExpressionType
impl Debug for ExpressionType
§impl From<&str> for ExpressionType
impl From<&str> for ExpressionType
§fn from(s: &str) -> ExpressionType
fn from(s: &str) -> ExpressionType
§impl FromStr for ExpressionType
impl FromStr for ExpressionType
§type Err = Infallible
type Err = Infallible
§fn from_str(s: &str) -> Result<ExpressionType, <ExpressionType as FromStr>::Err>
fn from_str(s: &str) -> Result<ExpressionType, <ExpressionType as FromStr>::Err>
s
to return a value of this type. Read more§impl Hash for ExpressionType
impl Hash for ExpressionType
§impl Ord for ExpressionType
impl Ord for ExpressionType
§impl PartialEq for ExpressionType
impl PartialEq for ExpressionType
§fn eq(&self, other: &ExpressionType) -> bool
fn eq(&self, other: &ExpressionType) -> bool
self
and other
values to be equal, and is used
by ==
.§impl PartialOrd for ExpressionType
impl PartialOrd for ExpressionType
§fn partial_cmp(&self, other: &ExpressionType) -> Option<Ordering>
fn partial_cmp(&self, other: &ExpressionType) -> 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 ExpressionType
impl StructuralEq for ExpressionType
impl StructuralPartialEq for ExpressionType
Auto Trait Implementations§
impl RefUnwindSafe for ExpressionType
impl Send for ExpressionType
impl Sync for ExpressionType
impl Unpin for ExpressionType
impl UnwindSafe for ExpressionType
Blanket Implementations§
§impl<'a, T, E> AsTaggedExplicit<'a, E> for Twhere
T: 'a,
impl<'a, T, E> AsTaggedExplicit<'a, E> for Twhere
T: 'a,
§impl<'a, T, E> AsTaggedImplicit<'a, E> for Twhere
T: 'a,
impl<'a, T, E> AsTaggedImplicit<'a, E> for Twhere
T: 'a,
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<T> CallHasher for T
impl<T> CallHasher for 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.