Struct ctxmap::CtxMap

pub struct CtxMap<S: Schema> { /* private fields */ }

A collection that can store references of different types and lifetimes.

Implementations

impl<S: Schema> CtxMap<S>

pub fn new() -> Self

Create a new CtxMap with initial values.

Example

ctxmap::schema!(S);
ctxmap::key!(S { KEY_A: u16 = 20 });
ctxmap::key!(S { KEY_B: u8 });

let m = ctxmap::CtxMap::new();
assert_eq!(m[&KEY_A], 20);
assert_eq!(m.get(&KEY_A), Some(&20));
assert_eq!(m.get(&KEY_B), None);

pub fn with<T: ?Sized + 'static, U>(
    &mut self,
    key: &'static Key<S, T>,
    value: &T,
    f: impl FnOnce(&mut CtxMapView<'_, S>) -> U
) -> U

Sets a value corresponding to the key only while f is being called.

Example

ctxmap::schema!(S);
ctxmap::key!(S { KEY_A: u16 = 20 });

let mut m = ctxmap::CtxMap::new();
assert_eq!(m[&KEY_A], 20);
m.with(&KEY_A, &30, |m| {
    assert_eq!(m[&KEY_A], 30);
});
assert_eq!(m[&KEY_A], 20);

pub fn view(&mut self) -> CtxMapView<'_, S>

Get CtxMapView that references self.

pub fn get<T: ?Sized>(&self, key: &'static Key<S, T>) -> Option<&T>

Returns a reference to the value corresponding to the key.

Example

ctxmap::schema!(S);
ctxmap::key!(S { KEY_A: u16 });

let mut m = ctxmap::CtxMap::new();
assert_eq!(m.get(&KEY_A), None);
m.with(&KEY_A, &10, |m| {
    assert_eq!(m.get(&KEY_A), Some(&10));
});
assert_eq!(m.get(&KEY_A), None);

Trait Implementations

impl<S: Schema> Default for CtxMap<S>

fn default() -> Self

Returns the “default value” for a type.

impl<S, T> Index<&'static Key<S, T>> for CtxMap<S> where
    S: Schema,
    T: ?Sized + 'static, 

type Output = T

The returned type after indexing.

fn index(&self, index: &'static Key<S, T>) -> &Self::Output

Performs the indexing (container[index]) operation.