Struct ContextMap 

pub struct ContextMap { /* private fields */ }

A type-keyed container of values.

Each registered value is stored under its TypeId, so a given type can only be registered once per ContextMap. Used by Cx to hold both the router-wide app context and the per-request request context; values are retrieved within a request via app_context or request_context.

Implementations

impl ContextMap

pub fn new() -> Self

Creates an empty ContextMap.

pub fn insert<T>(&mut self, value: T) -> Option<T>

where T: Any + Send + Sync,

Registers value under its concrete type T, returning the value previously registered for T, if any.

A type can hold only one value at a time, so registering a type that is already present replaces it and hands back the displaced value.

pub fn contains<T>(&self) -> bool

where T: Any + Send + Sync,

Returns true if a value of type T has been registered.

pub fn get<T>(&self) -> Option<&T>

where T: Any + Send + Sync,

Returns a reference to the registered value of type T, or None if no such value has been registered.

Within a request, prefer the app_context and request_context free functions over reaching for this directly.

pub fn get_mut<T>(&mut self) -> Option<&mut T>

where T: Any + Send + Sync,

Returns a mutable reference to the registered value of type T, or None if no such value has been registered.

Trait Implementations

impl Debug for ContextMap

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

Formats the value using the given formatter.

impl Default for ContextMap

fn default() -> ContextMap

Returns the “default value” for a type.