Struct Context 

pub struct Context { /* private fields */ }

A map that can store values of any type specified by AnyValueSpec.

Implementations

impl Context

pub fn new() -> Self

Creates a new empty Context.

pub fn initialize(&mut self, reg: &ContextKeyRegistry)

Initializes the context with a given ContextKeyRegistry.

pub fn insert<T: AnyValueSpec>(&mut self, key: ContextKey<T>, value: T::Item)

Inserts a value into the context.

pub fn get<T: AnyValueSpec>(&self, key: ContextKey<T>) -> Option<&T::Item>

Gets a reference to a value from the context.

pub fn get_or_insert<T: AnyValueSpec>( &mut self, key: ContextKey<T>, default: impl FnOnce() -> T::Item, ) -> &T::Item

Gets or inserts a value in the context. If the key does not exist, inserts the default value and returns a reference to it. Otherwise, returns a reference to the existing value.

pub fn get_mut<T: AnyValueSpec>( &mut self, key: ContextKey<T>, ) -> Option<&mut T::Item>

Gets a mutable reference to a value from the context.

pub fn get_or_insert_mut<T: AnyValueSpec>( &mut self, key: ContextKey<T>, default: impl FnOnce() -> T::Item, ) -> &mut T::Item

Gets or inserts a mutable reference to a value in the context. If the key does not exist, inserts the default value and returns a mutable reference to it. Otherwise, returns a mutable reference to the existing value.

pub fn remove<T: AnyValueSpec>(&mut self, key: ContextKey<T>) -> Option<T::Item>

Removes a value from the context. If the key does not exist, returns None. Otherwise, returns the removed value.

Trait Implementations

impl Default for Context

fn default() -> Self

Returns the “default value” for a type.