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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98

use std::any::{ Any, type_name };

#[macro_use]
mod as_macro;
pub use as_macro::*;

#[macro_use]
mod value;
pub use value::*;

#[macro_use]
mod key;
pub use key::*;

mod immutable;
pub use immutable::*;

pub trait AsAny {

    fn as_any_ref(&self) -> &dyn Any;

    fn as_any_mut(&mut self) -> &mut dyn Any;

}

impl<T: 'static> AsAny for T {
    fn as_any_ref(&self) -> &dyn Any {
        self
    }

    fn as_any_mut(&mut self) -> &mut dyn Any {
        self
    }
}

pub trait AnyExtension {
    fn type_name(&self) -> &'static str;
    fn memory_address(&self) -> usize;
    fn reference_equals(&self, other: &dyn Any) -> bool;
}

impl<T: ?Sized> AnyExtension for T {
    fn type_name(&self) -> &'static str {
        type_name::<Self>()
    }

    fn memory_address(&self) -> usize {
        self as *const T as *const () as usize
    }

    fn reference_equals(&self, other: &dyn Any) -> bool {
        self.memory_address() == other.memory_address()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::any::TypeId;

    #[test]
    fn as_any() {
        let d = 1;
        assert_eq!(d.as_any_ref().type_id(), TypeId::of::<i32>());

        let mut d = d;
        *d.as_any_mut().downcast_mut::<i32>().unwrap() = 2;
        assert_eq!(2, d);
    }

    #[test]
    fn any_extension() {
        let a: Box<dyn Any> = Box::new(10);
        println!("type_name: {}, memory_address: {:?}",
            a.as_ref().type_name(), a.as_ref().memory_address());

        assert_eq!(type_name::<i32>(), 10.type_name());
        assert_eq!(type_name::<dyn Any>(), a.as_ref().type_name());
        assert_eq!(type_name::<Box<dyn Any>>(), a.type_name());

        assert_eq!(a.as_ref().downcast_ref::<i32>().unwrap() as *const i32 as usize,
            a.as_ref().memory_address());
        assert_eq!(&a as *const Box::<dyn Any> as *const () as usize, a.memory_address());

        let b: Box<dyn Any> = Box::new(10);
        assert!(!a.reference_equals(b.as_any_ref()));

        let x = Box::new(10);
        assert_eq!(x, x);
        assert!(x.reference_equals(x.as_any_ref()));

        let y = Box::new(10);
        assert_eq!(x, y);
        assert!(!x.reference_equals(y.as_any_ref()));
        assert!(!x.as_ref().reference_equals(y.as_ref().as_any_ref()));
    }

}