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