#[non_exhaustive]
pub enum LaunchTemplateInstanceMetadataProtocolIpv6 {
Disabled,
Enabled,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against LaunchTemplateInstanceMetadataProtocolIpv6
, 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 launchtemplateinstancemetadataprotocolipv6 = unimplemented!();
match launchtemplateinstancemetadataprotocolipv6 {
LaunchTemplateInstanceMetadataProtocolIpv6::Disabled => { /* ... */ },
LaunchTemplateInstanceMetadataProtocolIpv6::Enabled => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when launchtemplateinstancemetadataprotocolipv6
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant LaunchTemplateInstanceMetadataProtocolIpv6::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
LaunchTemplateInstanceMetadataProtocolIpv6::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 LaunchTemplateInstanceMetadataProtocolIpv6::NewFeature
is defined.
Specifically, when launchtemplateinstancemetadataprotocolipv6
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on LaunchTemplateInstanceMetadataProtocolIpv6::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
Disabled
Enabled
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
source§impl LaunchTemplateInstanceMetadataProtocolIpv6
impl LaunchTemplateInstanceMetadataProtocolIpv6
sourcepub fn as_str(&self) -> &str
pub fn as_str(&self) -> &str
Returns the &str
value of the enum member.
Examples found in repository?
More examples
4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524
pub fn serialize_structure_crate_model_launch_template_instance_metadata_options_request(
mut writer: aws_smithy_query::QueryValueWriter,
input: &crate::model::LaunchTemplateInstanceMetadataOptionsRequest,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
#[allow(unused_mut)]
let mut scope_1278 = writer.prefix("HttpTokens");
if let Some(var_1279) = &input.http_tokens {
scope_1278.string(var_1279.as_str());
}
#[allow(unused_mut)]
let mut scope_1280 = writer.prefix("HttpPutResponseHopLimit");
if let Some(var_1281) = &input.http_put_response_hop_limit {
scope_1280.number(
#[allow(clippy::useless_conversion)]
aws_smithy_types::Number::NegInt((*var_1281).into()),
);
}
#[allow(unused_mut)]
let mut scope_1282 = writer.prefix("HttpEndpoint");
if let Some(var_1283) = &input.http_endpoint {
scope_1282.string(var_1283.as_str());
}
#[allow(unused_mut)]
let mut scope_1284 = writer.prefix("HttpProtocolIpv6");
if let Some(var_1285) = &input.http_protocol_ipv6 {
scope_1284.string(var_1285.as_str());
}
#[allow(unused_mut)]
let mut scope_1286 = writer.prefix("InstanceMetadataTags");
if let Some(var_1287) = &input.instance_metadata_tags {
scope_1286.string(var_1287.as_str());
}
Ok(())
}
Trait Implementations§
source§impl Clone for LaunchTemplateInstanceMetadataProtocolIpv6
impl Clone for LaunchTemplateInstanceMetadataProtocolIpv6
source§fn clone(&self) -> LaunchTemplateInstanceMetadataProtocolIpv6
fn clone(&self) -> LaunchTemplateInstanceMetadataProtocolIpv6
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Ord for LaunchTemplateInstanceMetadataProtocolIpv6
impl Ord for LaunchTemplateInstanceMetadataProtocolIpv6
source§fn cmp(&self, other: &LaunchTemplateInstanceMetadataProtocolIpv6) -> Ordering
fn cmp(&self, other: &LaunchTemplateInstanceMetadataProtocolIpv6) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<LaunchTemplateInstanceMetadataProtocolIpv6> for LaunchTemplateInstanceMetadataProtocolIpv6
impl PartialEq<LaunchTemplateInstanceMetadataProtocolIpv6> for LaunchTemplateInstanceMetadataProtocolIpv6
source§fn eq(&self, other: &LaunchTemplateInstanceMetadataProtocolIpv6) -> bool
fn eq(&self, other: &LaunchTemplateInstanceMetadataProtocolIpv6) -> bool
source§impl PartialOrd<LaunchTemplateInstanceMetadataProtocolIpv6> for LaunchTemplateInstanceMetadataProtocolIpv6
impl PartialOrd<LaunchTemplateInstanceMetadataProtocolIpv6> for LaunchTemplateInstanceMetadataProtocolIpv6
source§fn partial_cmp(
&self,
other: &LaunchTemplateInstanceMetadataProtocolIpv6
) -> Option<Ordering>
fn partial_cmp(
&self,
other: &LaunchTemplateInstanceMetadataProtocolIpv6
) -> 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 LaunchTemplateInstanceMetadataProtocolIpv6
impl StructuralEq for LaunchTemplateInstanceMetadataProtocolIpv6
impl StructuralPartialEq for LaunchTemplateInstanceMetadataProtocolIpv6
Auto Trait Implementations§
impl RefUnwindSafe for LaunchTemplateInstanceMetadataProtocolIpv6
impl Send for LaunchTemplateInstanceMetadataProtocolIpv6
impl Sync for LaunchTemplateInstanceMetadataProtocolIpv6
impl Unpin for LaunchTemplateInstanceMetadataProtocolIpv6
impl UnwindSafe for LaunchTemplateInstanceMetadataProtocolIpv6
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.