Struct SchemaExtensionKey 

pub struct SchemaExtensionKey<T> { /* private fields */ }

Identifies one kind of derived data cached on schemas, and computes it.

Declare keys as statics. Each key is assigned a process-unique slot the first time it is used, and slots are never reused.

Schema::extension takes a &'static key, so a const key, which would be a new key with a new slot at every use, is rejected at compile time:

use aws_smithy_schema::extension::SchemaExtensionKey;
use aws_smithy_schema::prelude;

const KEY: SchemaExtensionKey<u8> = SchemaExtensionKey::new(|_| 0);
let _ = prelude::STRING.extension(&KEY);

Implementations

impl<T> SchemaExtensionKey<T>

pub const fn new(provider: fn(&Schema<'_>) -> T) -> Self

Creates a key whose values are derived by provider.

Trait Implementations

impl<T> Debug for SchemaExtensionKey<T>

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

Formats the value using the given formatter.