src/test/ui/issues/issue-22992.rs

   1 // run-pass
   2
   3 struct X { val: i32 }
   4 impl std::ops::Deref for X {
   5     type Target = i32;
   6     fn deref(&self) -> &i32 { &self.val }
   7 }
   8
   9
  10 trait            M                   { fn m(self); }
  11 impl             M for i32           { fn m(self) { println!("i32::m()"); } }
  12 impl             M for X             { fn m(self) { println!("X::m()"); } }
  13 impl<'a>         M for &'a X         { fn m(self) { println!("&X::m()"); } }
  14 impl<'a, 'b>     M for &'a &'b X     { fn m(self) { println!("&&X::m()"); } }
  15 impl<'a, 'b, 'c> M for &'a &'b &'c X { fn m(self) { println!("&&&X::m()"); } }
  16
  17 trait            RefM                   { fn refm(&self); }
  18 impl             RefM for i32           { fn refm(&self) { println!("i32::refm()"); } }
  19 impl             RefM for X             { fn refm(&self) { println!("X::refm()"); } }
  20 impl<'a>         RefM for &'a X         { fn refm(&self) { println!("&X::refm()"); } }
  21 impl<'a, 'b>     RefM for &'a &'b X     { fn refm(&self) { println!("&&X::refm()"); } }
  22 impl<'a, 'b, 'c> RefM for &'a &'b &'c X { fn refm(&self) { println!("&&&X::refm()"); } }
  23
  24 struct Y { val: i32 }
  25 impl std::ops::Deref for Y {
  26     type Target = i32;
  27     fn deref(&self) -> &i32 { &self.val }
  28 }
  29
  30 struct Z { val: Y }
  31 impl std::ops::Deref for Z {
  32     type Target = Y;
  33     fn deref(&self) -> &Y { &self.val }
  34 }
  35
  36 struct A;
  37 impl std::marker::Copy for A {}
  38 impl Clone for A { fn clone(&self) -> Self { *self } }
  39 impl             M for             A { fn m(self) { println!("A::m()"); } }
  40 impl<'a, 'b, 'c> M for &'a &'b &'c A { fn m(self) { println!("&&&A::m()"); } }
  41 impl             RefM for             A { fn refm(&self) { println!("A::refm()"); } }
  42 impl<'a, 'b, 'c> RefM for &'a &'b &'c A { fn refm(&self) { println!("&&&A::refm()"); } }
  43
  44 fn main() {
  45     // I'll use @ to denote left side of the dot operator
  46     (*X{val:42}).m();        // i32::refm() , self == @
  47     X{val:42}.m();           // X::m()      , self == @
  48     (&X{val:42}).m();        // &X::m()     , self == @
  49     (&&X{val:42}).m();       // &&X::m()    , self == @
  50     (&&&X{val:42}).m();      // &&&X:m()    , self == @
  51     (&&&&X{val:42}).m();     // &&&X::m()   , self == *@
  52     (&&&&&X{val:42}).m();    // &&&X::m()   , self == **@
  53
  54     (*X{val:42}).refm();     // i32::refm() , self == @
  55     X{val:42}.refm();        // X::refm()   , self == @
  56     (&X{val:42}).refm();     // X::refm()   , self == *@
  57     (&&X{val:42}).refm();    // &X::refm()  , self == *@
  58     (&&&X{val:42}).refm();   // &&X::refm() , self == *@
  59     (&&&&X{val:42}).refm();  // &&&X::refm(), self == *@
  60     (&&&&&X{val:42}).refm(); // &&&X::refm(), self == **@
  61
  62     Y{val:42}.refm();        // i32::refm() , self == *@
  63     Z{val:Y{val:42}}.refm(); // i32::refm() , self == **@
  64
  65     A.m();                   // A::m()      , self == @
  66     // without the Copy trait, (&A).m() would be a compilation error:
  67     // cannot move out of borrowed content
  68     (&A).m();                // A::m()      , self == *@
  69     (&&A).m();               // &&&A::m()   , self == &@
  70     (&&&A).m();              // &&&A::m()   , self == @
  71     A.refm();                // A::refm()   , self == @
  72     (&A).refm();             // A::refm()   , self == *@
  73     (&&A).refm();            // A::refm()   , self == **@
  74     (&&&A).refm();           // &&&A::refm(), self == @
  75 }