#[non_exhaustive]
pub enum RouteState {
    Active,
    Blackhole,
    Unknown(UnknownVariantValue),
}
Expand description

When writing a match expression against RouteState, 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 routestate = unimplemented!();
match routestate {
    RouteState::Active => { /* ... */ },
    RouteState::Blackhole => { /* ... */ },
    other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
    _ => { /* ... */ },
}

The above code demonstrates that when routestate represents NewFeature, the execution path will lead to the second last match arm, even though the enum does not contain a variant RouteState::NewFeature in the current version of SDK. The reason is that the variable other, created by the @ operator, is bound to RouteState::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 RouteState::NewFeature is defined. Specifically, when routestate represents NewFeature, the execution path will hit the second last match arm as before by virtue of calling as_str on RouteState::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.
§

Active

§

Blackhole

§

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 8262)
8261
8262
8263
    fn as_ref(&self) -> &str {
        self.as_str()
    }
More examples
Hide additional examples
src/json_ser.rs (line 541)
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
pub fn serialize_structure_crate_input_get_network_routes_input(
    object: &mut aws_smithy_json::serialize::JsonObjectWriter,
    input: &crate::input::GetNetworkRoutesInput,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    if let Some(var_121) = &input.destination_filters {
        #[allow(unused_mut)]
        let mut object_122 = object.key("DestinationFilters").start_object();
        for (key_123, value_124) in var_121 {
            {
                let mut array_125 = object_122.key(key_123.as_str()).start_array();
                for item_126 in value_124 {
                    {
                        array_125.value().string(item_126.as_str());
                    }
                }
                array_125.finish();
            }
        }
        object_122.finish();
    }
    if let Some(var_127) = &input.exact_cidr_matches {
        let mut array_128 = object.key("ExactCidrMatches").start_array();
        for item_129 in var_127 {
            {
                array_128.value().string(item_129.as_str());
            }
        }
        array_128.finish();
    }
    if let Some(var_130) = &input.longest_prefix_matches {
        let mut array_131 = object.key("LongestPrefixMatches").start_array();
        for item_132 in var_130 {
            {
                array_131.value().string(item_132.as_str());
            }
        }
        array_131.finish();
    }
    if let Some(var_133) = &input.prefix_list_ids {
        let mut array_134 = object.key("PrefixListIds").start_array();
        for item_135 in var_133 {
            {
                array_134.value().string(item_135.as_str());
            }
        }
        array_134.finish();
    }
    if let Some(var_136) = &input.route_table_identifier {
        #[allow(unused_mut)]
        let mut object_137 = object.key("RouteTableIdentifier").start_object();
        crate::json_ser::serialize_structure_crate_model_route_table_identifier(
            &mut object_137,
            var_136,
        )?;
        object_137.finish();
    }
    if let Some(var_138) = &input.states {
        let mut array_139 = object.key("States").start_array();
        for item_140 in var_138 {
            {
                array_139.value().string(item_140.as_str());
            }
        }
        array_139.finish();
    }
    if let Some(var_141) = &input.subnet_of_matches {
        let mut array_142 = object.key("SubnetOfMatches").start_array();
        for item_143 in var_141 {
            {
                array_142.value().string(item_143.as_str());
            }
        }
        array_142.finish();
    }
    if let Some(var_144) = &input.supernet_of_matches {
        let mut array_145 = object.key("SupernetOfMatches").start_array();
        for item_146 in var_144 {
            {
                array_145.value().string(item_146.as_str());
            }
        }
        array_145.finish();
    }
    if let Some(var_147) = &input.types {
        let mut array_148 = object.key("Types").start_array();
        for item_149 in var_147 {
            {
                array_148.value().string(item_149.as_str());
            }
        }
        array_148.finish();
    }
    Ok(())
}

Returns all the &str values of the enum members.

Trait Implementations§

Converts this type into a shared reference of the (usually inferred) input type.
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Converts to this type from the input type.
The associated error which can be returned from parsing.
Parses a string s to return a value of this type. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
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
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Compare self to key and return true if they are equal.

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more