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
|
// run-pass
struct X { val: i32 }
impl std::ops::Deref for X {
type Target = i32;
fn deref(&self) -> &i32 { &self.val }
}
trait M { fn m(self); }
impl M for i32 { fn m(self) { println!("i32::m()"); } }
impl M for X { fn m(self) { println!("X::m()"); } }
impl<'a> M for &'a X { fn m(self) { println!("&X::m()"); } }
impl<'a, 'b> M for &'a &'b X { fn m(self) { println!("&&X::m()"); } }
impl<'a, 'b, 'c> M for &'a &'b &'c X { fn m(self) { println!("&&&X::m()"); } }
trait RefM { fn refm(&self); }
impl RefM for i32 { fn refm(&self) { println!("i32::refm()"); } }
impl RefM for X { fn refm(&self) { println!("X::refm()"); } }
impl<'a> RefM for &'a X { fn refm(&self) { println!("&X::refm()"); } }
impl<'a, 'b> RefM for &'a &'b X { fn refm(&self) { println!("&&X::refm()"); } }
impl<'a, 'b, 'c> RefM for &'a &'b &'c X { fn refm(&self) { println!("&&&X::refm()"); } }
struct Y { val: i32 }
impl std::ops::Deref for Y {
type Target = i32;
fn deref(&self) -> &i32 { &self.val }
}
struct Z { val: Y }
impl std::ops::Deref for Z {
type Target = Y;
fn deref(&self) -> &Y { &self.val }
}
struct A;
impl std::marker::Copy for A {}
impl Clone for A { fn clone(&self) -> Self { *self } }
impl M for A { fn m(self) { println!("A::m()"); } }
impl<'a, 'b, 'c> M for &'a &'b &'c A { fn m(self) { println!("&&&A::m()"); } }
impl RefM for A { fn refm(&self) { println!("A::refm()"); } }
impl<'a, 'b, 'c> RefM for &'a &'b &'c A { fn refm(&self) { println!("&&&A::refm()"); } }
fn main() {
// I'll use @ to denote left side of the dot operator
(*X{val:42}).m(); // i32::refm() , self == @
X{val:42}.m(); // X::m() , self == @
(&X{val:42}).m(); // &X::m() , self == @
(&&X{val:42}).m(); // &&X::m() , self == @
(&&&X{val:42}).m(); // &&&X:m() , self == @
(&&&&X{val:42}).m(); // &&&X::m() , self == *@
(&&&&&X{val:42}).m(); // &&&X::m() , self == **@
(*X{val:42}).refm(); // i32::refm() , self == @
X{val:42}.refm(); // X::refm() , self == @
(&X{val:42}).refm(); // X::refm() , self == *@
(&&X{val:42}).refm(); // &X::refm() , self == *@
(&&&X{val:42}).refm(); // &&X::refm() , self == *@
(&&&&X{val:42}).refm(); // &&&X::refm(), self == *@
(&&&&&X{val:42}).refm(); // &&&X::refm(), self == **@
Y{val:42}.refm(); // i32::refm() , self == *@
Z{val:Y{val:42}}.refm(); // i32::refm() , self == **@
A.m(); // A::m() , self == @
// without the Copy trait, (&A).m() would be a compilation error:
// cannot move out of borrowed content
(&A).m(); // A::m() , self == *@
(&&A).m(); // &&&A::m() , self == &@
(&&&A).m(); // &&&A::m() , self == @
A.refm(); // A::refm() , self == @
(&A).refm(); // A::refm() , self == *@
(&&A).refm(); // A::refm() , self == **@
(&&&A).refm(); // &&&A::refm(), self == @
}
|
