Enum aws_sdk_ec2::model::HttpTokensState

#[non_exhaustive]
pub enum HttpTokensState {
    Optional,
    Required,
    Unknown(UnknownVariantValue),
}

When writing a match expression against HttpTokensState, 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 httptokensstate = unimplemented!();
match httptokensstate {
    HttpTokensState::Optional => { /* ... */ },
    HttpTokensState::Required => { /* ... */ },
    other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
    _ => { /* ... */ },
}

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

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.

Optional

Required

Unknown(UnknownVariantValue)

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

Implementations

impl HttpTokensState

pub fn as_str(&self) -> &str

Returns the &str value of the enum member.

Examples found in repository

src/model.rs (line 11514)

    fn as_ref(&self) -> &str {
        self.as_str()
    }

src/query_ser.rs (line 3541)

pub fn serialize_structure_crate_model_instance_metadata_options_request(
    mut writer: aws_smithy_query::QueryValueWriter,
    input: &crate::model::InstanceMetadataOptionsRequest,
) -> Result<(), aws_smithy_http::operation::error::SerializationError> {
    #[allow(unused_mut)]
    let mut scope_1017 = writer.prefix("HttpTokens");
    if let Some(var_1018) = &input.http_tokens {
        scope_1017.string(var_1018.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_1019 = writer.prefix("HttpPutResponseHopLimit");
    if let Some(var_1020) = &input.http_put_response_hop_limit {
        scope_1019.number(
            #[allow(clippy::useless_conversion)]
            aws_smithy_types::Number::NegInt((*var_1020).into()),
        );
    }
    #[allow(unused_mut)]
    let mut scope_1021 = writer.prefix("HttpEndpoint");
    if let Some(var_1022) = &input.http_endpoint {
        scope_1021.string(var_1022.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_1023 = writer.prefix("HttpProtocolIpv6");
    if let Some(var_1024) = &input.http_protocol_ipv6 {
        scope_1023.string(var_1024.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_1025 = writer.prefix("InstanceMetadataTags");
    if let Some(var_1026) = &input.instance_metadata_tags {
        scope_1025.string(var_1026.as_str());
    }
    Ok(())
}

src/operation_ser.rs (line 18044)

pub fn serialize_operation_crate_operation_modify_instance_metadata_options(
    input: &crate::input::ModifyInstanceMetadataOptionsInput,
) -> 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, "ModifyInstanceMetadataOptions", "2016-11-15");
    #[allow(unused_mut)]
    let mut scope_5068 = writer.prefix("InstanceId");
    if let Some(var_5069) = &input.instance_id {
        scope_5068.string(var_5069);
    }
    #[allow(unused_mut)]
    let mut scope_5070 = writer.prefix("HttpTokens");
    if let Some(var_5071) = &input.http_tokens {
        scope_5070.string(var_5071.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_5072 = writer.prefix("HttpPutResponseHopLimit");
    if let Some(var_5073) = &input.http_put_response_hop_limit {
        scope_5072.number(
            #[allow(clippy::useless_conversion)]
            aws_smithy_types::Number::NegInt((*var_5073).into()),
        );
    }
    #[allow(unused_mut)]
    let mut scope_5074 = writer.prefix("HttpEndpoint");
    if let Some(var_5075) = &input.http_endpoint {
        scope_5074.string(var_5075.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_5076 = writer.prefix("DryRun");
    if let Some(var_5077) = &input.dry_run {
        scope_5076.boolean(*var_5077);
    }
    #[allow(unused_mut)]
    let mut scope_5078 = writer.prefix("HttpProtocolIpv6");
    if let Some(var_5079) = &input.http_protocol_ipv6 {
        scope_5078.string(var_5079.as_str());
    }
    #[allow(unused_mut)]
    let mut scope_5080 = writer.prefix("InstanceMetadataTags");
    if let Some(var_5081) = &input.instance_metadata_tags {
        scope_5080.string(var_5081.as_str());
    }
    writer.finish();
    Ok(aws_smithy_http::body::SdkBody::from(out))
}

pub const fn values() -> &'static [&'static str]

Returns all the &str values of the enum members.

Trait Implementations

impl AsRef<str> for HttpTokensState

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for HttpTokensState

fn clone(&self) -> HttpTokensState

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for HttpTokensState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&str> for HttpTokensState

fn from(s: &str) -> Self

Converts to this type from the input type.

impl FromStr for HttpTokensState

type Err = Infallible

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for HttpTokensState

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for HttpTokensState

fn cmp(&self, other: &HttpTokensState) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere
    Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<HttpTokensState> for HttpTokensState

fn eq(&self, other: &HttpTokensState) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<HttpTokensState> for HttpTokensState

fn partial_cmp(&self, other: &HttpTokensState) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for HttpTokensState

impl StructuralEq for HttpTokensState

impl StructuralPartialEq for HttpTokensState