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