dynex_core 0.1.1

Core functionality for the `dynex` crate.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53

use core::any::Any;

/// This trait is the base trait for all the `dynex` traits,
/// and adds methods to retrieve a `&dyn Any`.
pub trait Dyn: Any {
    fn as_any(&self) -> &dyn Any;
    fn as_any_mut(&mut self) -> &mut dyn Any;
    fn as_any_box(self: Box<Self>) -> Box<dyn Any>;
}

impl<T: Any> Dyn for T {
    #[inline(always)]
    fn as_any(&self) -> &dyn Any {
        self
    }

    #[inline(always)]
    fn as_any_mut(&mut self) -> &mut dyn Any {
        self
    }

    #[inline(always)]
    fn as_any_box(self: Box<Self>) -> Box<dyn Any> {
        self
    }
}

/// This is a shim around `Dyn` to avoid some boilerplate code.
/// It is a separate trait because it is also implemented
/// on runtime polymorphic traits (which are `!Sized`).
pub trait Downcast: Dyn {
    /// Returns `true` if the boxed type is the same as `T`.
    #[inline]
    fn is<T: Dyn>(&self) -> bool {
        self.as_any().is::<T>()
    }

    /// Returns some reference to the inner value if it is of type `T`,
    /// or `None` if it isn't.
    #[inline]
    fn downcast_ref<T: Dyn>(&self) -> Option<&T> {
        self.as_any().downcast_ref()
    }

    /// Returns some mutable reference to the inner value
    /// if it is of type `T`, or `None` if it isn't.
    #[inline]
    fn downcast_mut<T: Dyn>(&mut self) -> Option<&mut T> {
        self.as_any_mut().downcast_mut()
    }
}

impl<T: ?Sized + Dyn> Downcast for T {}