Enum aws_sdk_s3::types::Protocol
source · #[non_exhaustive]pub enum Protocol {
Http,
Https,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against Protocol
, 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 protocol = unimplemented!();
match protocol {
Protocol::Http => { /* ... */ },
Protocol::Https => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when protocol
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant Protocol::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
Protocol::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 Protocol::NewFeature
is defined.
Specifically, when protocol
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on Protocol::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
Http
Https
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 Protocol
impl Ord for Protocol
source§impl PartialOrd for Protocol
impl PartialOrd for Protocol
impl Eq for Protocol
impl StructuralPartialEq for Protocol
Auto Trait Implementations§
impl Freeze for Protocol
impl RefUnwindSafe for Protocol
impl Send for Protocol
impl Sync for Protocol
impl Unpin for Protocol
impl UnwindSafe for Protocol
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
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.