src/test/run-pass/fsu-moves-and-copies.rs

   1 // Copyright 2012-2013 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 // Issue 4691: Ensure that functional-struct-updates operates
  12 // correctly and moves rather than copy when appropriate.
  13
  14 #![allow(unknown_features)]
  15 #![feature(box_syntax)]
  16
  17 use std::marker::NoCopy as NP;
  18
  19 struct ncint { np: NP, v: int }
  20 fn ncint(v: int) -> ncint { ncint { np: NP, v: v } }
  21
  22 struct NoFoo { copied: int, nocopy: ncint, }
  23 impl NoFoo {
  24     fn new(x:int,y:int) -> NoFoo { NoFoo { copied: x, nocopy: ncint(y) } }
  25 }
  26
  27 struct MoveFoo { copied: int, moved: Box<int>, }
  28 impl MoveFoo {
  29     fn new(x:int,y:int) -> MoveFoo { MoveFoo { copied: x, moved: box y } }
  30 }
  31
  32 struct DropNoFoo { inner: NoFoo }
  33 impl DropNoFoo {
  34     fn new(x:int,y:int) -> DropNoFoo { DropNoFoo { inner: NoFoo::new(x,y) } }
  35 }
  36 impl Drop for DropNoFoo { fn drop(&mut self) { } }
  37
  38 struct DropMoveFoo { inner: MoveFoo }
  39 impl DropMoveFoo {
  40     fn new(x:int,y:int) -> DropMoveFoo { DropMoveFoo { inner: MoveFoo::new(x,y) } }
  41 }
  42 impl Drop for DropMoveFoo { fn drop(&mut self) { } }
  43
  44
  45 fn test0() {
  46     // just copy implicitly copyable fields from `f`, no moves
  47     // (and thus it is okay that these are Drop; compare against
  48     // compile-fail test: borrowck-struct-update-with-dtor.rs).
  49
  50     // Case 1: Nocopyable
  51     let f = DropNoFoo::new(1, 2);
  52     let b = DropNoFoo { inner: NoFoo { nocopy: ncint(3), ..f.inner }};
  53     let c = DropNoFoo { inner: NoFoo { nocopy: ncint(4), ..f.inner }};
  54     assert_eq!(f.inner.copied,    1);
  55     assert_eq!(f.inner.nocopy.v, 2);
  56
  57     assert_eq!(b.inner.copied,    1);
  58     assert_eq!(b.inner.nocopy.v, 3);
  59
  60     assert_eq!(c.inner.copied,    1);
  61     assert_eq!(c.inner.nocopy.v, 4);
  62
  63     // Case 2: Owned
  64     let f = DropMoveFoo::new(5, 6);
  65     let b = DropMoveFoo { inner: MoveFoo { moved: box 7, ..f.inner }};
  66     let c = DropMoveFoo { inner: MoveFoo { moved: box 8, ..f.inner }};
  67     assert_eq!(f.inner.copied,    5);
  68     assert_eq!(*f.inner.moved,    6);
  69
  70     assert_eq!(b.inner.copied,    5);
  71     assert_eq!(*b.inner.moved,    7);
  72
  73     assert_eq!(c.inner.copied,    5);
  74     assert_eq!(*c.inner.moved,    8);
  75 }
  76
  77 fn test1() {
  78     // copying move-by-default fields from `f`, so it moves:
  79     let f = MoveFoo::new(11, 12);
  80
  81     let b = MoveFoo {moved: box 13, ..f};
  82     let c = MoveFoo {copied: 14, ..f};
  83     assert_eq!(b.copied,    11);
  84     assert_eq!(*b.moved,    13);
  85     assert_eq!(c.copied,    14);
  86     assert_eq!(*c.moved,    12);
  87 }
  88
  89 fn test2() {
  90     // move non-copyable field
  91     let f = NoFoo::new(21, 22);
  92     let b = NoFoo {nocopy: ncint(23), ..f};
  93     let c = NoFoo {copied: 24, ..f};
  94     assert_eq!(b.copied,    21);
  95     assert_eq!(b.nocopy.v, 23);
  96     assert_eq!(c.copied,    24);
  97     assert_eq!(c.nocopy.v, 22);
  98 }
  99
 100 pub fn main() {
 101     test0();
 102     test1();
 103     test2();
 104 }