#[non_exhaustive]
pub enum SubnetCidrReservationType {
    Explicit,
    Prefix,
    Unknown(UnknownVariantValue),
}
Expand description

When writing a match expression against SubnetCidrReservationType, 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 subnetcidrreservationtype = unimplemented!();
match subnetcidrreservationtype {
    SubnetCidrReservationType::Explicit => { /* ... */ },
    SubnetCidrReservationType::Prefix => { /* ... */ },
    other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
    _ => { /* ... */ },
}

The above code demonstrates that when subnetcidrreservationtype represents NewFeature, the execution path will lead to the second last match arm, even though the enum does not contain a variant SubnetCidrReservationType::NewFeature in the current version of SDK. The reason is that the variable other, created by the @ operator, is bound to SubnetCidrReservationType::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 SubnetCidrReservationType::NewFeature is defined. Specifically, when subnetcidrreservationtype represents NewFeature, the execution path will hit the second last match arm as before by virtue of calling as_str on SubnetCidrReservationType::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
Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.
§

Explicit

§

Prefix

§

Unknown(UnknownVariantValue)

Unknown contains new variants that have been added since this code was generated.

Implementations§

Returns the &str value of the enum member.

Examples found in repository?
src/model.rs (line 56923)
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    fn as_ref(&self) -> &str {
        self.as_str()
    }
More examples
Hide additional examples
src/operation_ser.rs (line 4522)
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pub fn serialize_operation_crate_operation_create_subnet_cidr_reservation(
    input: &crate::input::CreateSubnetCidrReservationInput,
) -> Result<aws_smithy_http::body::SdkBody, aws_smithy_http::operation::error::SerializationError> {
    let mut out = String::new();
    #[allow(unused_mut)]
    let mut writer =
        aws_smithy_query::QueryWriter::new(&mut out, "CreateSubnetCidrReservation", "2016-11-15");
    #[allow(unused_mut)]
    let mut scope_1312 = writer.prefix("SubnetId");
    if let Some(var_1313) = &input.subnet_id {
        scope_1312.string(var_1313);
    }
    #[allow(unused_mut)]
    let mut scope_1314 = writer.prefix("Cidr");
    if let Some(var_1315) = &input.cidr {
        scope_1314.string(var_1315);
    }
    #[allow(unused_mut)]
    let mut scope_1316 = writer.prefix("ReservationType");
    if let Some(var_1317) = &input.reservation_type {
        scope_1316.string(var_1317.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_1318 = writer.prefix("Description");
    if let Some(var_1319) = &input.description {
        scope_1318.string(var_1319);
    }
    #[allow(unused_mut)]
    let mut scope_1320 = writer.prefix("DryRun");
    if let Some(var_1321) = &input.dry_run {
        scope_1320.boolean(*var_1321);
    }
    #[allow(unused_mut)]
    let mut scope_1322 = writer.prefix("TagSpecification");
    if let Some(var_1323) = &input.tag_specifications {
        let mut list_1325 = scope_1322.start_list(true, Some("item"));
        for item_1324 in var_1323 {
            #[allow(unused_mut)]
            let mut entry_1326 = list_1325.entry();
            crate::query_ser::serialize_structure_crate_model_tag_specification(
                entry_1326, item_1324,
            )?;
        }
        list_1325.finish();
    }
    writer.finish();
    Ok(aws_smithy_http::body::SdkBody::from(out))
}

Returns all the &str values of the enum members.

Trait Implementations§

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This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
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Compare self to key and return true if they are equal.

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