Enum aws_sdk_transfer::types::MapType
source · #[non_exhaustive]pub enum MapType {
Directory,
File,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against MapType
, 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 maptype = unimplemented!();
match maptype {
MapType::Directory => { /* ... */ },
MapType::File => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when maptype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant MapType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
MapType::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 MapType::NewFeature
is defined.
Specifically, when maptype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on MapType::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
Directory
File
Unknown(UnknownVariantValue)
Unknown
. See the docs on this enum for the correct way to handle unknown variants.Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl Ord for MapType
impl Ord for MapType
source§impl PartialEq for MapType
impl PartialEq for MapType
source§impl PartialOrd for MapType
impl PartialOrd for MapType
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 MapType
impl StructuralEq for MapType
impl StructuralPartialEq for MapType
Auto Trait Implementations§
impl RefUnwindSafe for MapType
impl Send for MapType
impl Sync for MapType
impl Unpin for MapType
impl UnwindSafe for MapType
Blanket Implementations§
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<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,
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§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,
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.