src/test/run-pass/dst-struct-sole.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // As dst-struct.rs, but the unsized field is the only field in the struct.
  12
  13 // pretty-expanded FIXME #23616
  14
  15 struct Fat<T: ?Sized> {
  16     ptr: T
  17 }
  18
  19 // x is a fat pointer
  20 fn foo(x: &Fat<[isize]>) {
  21     let y = &x.ptr;
  22     assert!(x.ptr.len() == 3);
  23     assert!(y[0] == 1);
  24     assert!(x.ptr[1] == 2);
  25 }
  26
  27 fn foo2<T:ToBar>(x: &Fat<[T]>) {
  28     let y = &x.ptr;
  29     let bar = Bar;
  30     assert!(x.ptr.len() == 3);
  31     assert!(y[0].to_bar() == bar);
  32     assert!(x.ptr[1].to_bar() == bar);
  33 }
  34
  35 #[derive(Copy, Clone, PartialEq, Eq)]
  36 struct Bar;
  37
  38 trait ToBar {
  39     fn to_bar(&self) -> Bar;
  40 }
  41
  42 impl ToBar for Bar {
  43     fn to_bar(&self) -> Bar {
  44         *self
  45     }
  46 }
  47
  48 pub fn main() {
  49     // With a vec of ints.
  50     let f1 = Fat { ptr: [1, 2, 3] };
  51     foo(&f1);
  52     let f2 = &f1;
  53     foo(f2);
  54     let f3: &Fat<[isize]> = f2;
  55     foo(f3);
  56     let f4: &Fat<[isize]> = &f1;
  57     foo(f4);
  58     let f5: &Fat<[isize]> = &Fat { ptr: [1, 2, 3] };
  59     foo(f5);
  60
  61     // With a vec of Bars.
  62     let bar = Bar;
  63     let f1 = Fat { ptr: [bar, bar, bar] };
  64     foo2(&f1);
  65     let f2 = &f1;
  66     foo2(f2);
  67     let f3: &Fat<[Bar]> = f2;
  68     foo2(f3);
  69     let f4: &Fat<[Bar]> = &f1;
  70     foo2(f4);
  71     let f5: &Fat<[Bar]> = &Fat { ptr: [bar, bar, bar] };
  72     foo2(f5);
  73
  74     // Assignment.
  75     let f5: &mut Fat<[isize]> = &mut Fat { ptr: [1, 2, 3] };
  76     f5.ptr[1] = 34;
  77     assert!(f5.ptr[0] == 1);
  78     assert!(f5.ptr[1] == 34);
  79     assert!(f5.ptr[2] == 3);
  80
  81     // Zero size vec.
  82     let f5: &Fat<[isize]> = &Fat { ptr: [] };
  83     assert!(f5.ptr.len() == 0);
  84     let f5: &Fat<[Bar]> = &Fat { ptr: [] };
  85     assert!(f5.ptr.len() == 0);
  86 }