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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 | ||
62682a34 | 11 | #![feature(nonzero, core)] |
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12 | |
13 | extern crate core; | |
14 | ||
15 | use core::nonzero::NonZero; | |
16 | use std::mem::size_of; | |
17 | use std::rc::Rc; | |
18 | use std::sync::Arc; | |
19 | ||
85aaf69f | 20 | trait Trait { fn dummy(&self) { } } |
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21 | trait Mirror { type Image; } |
22 | impl<T> Mirror for T { type Image = T; } | |
23 | struct ParamTypeStruct<T>(T); | |
24 | struct AssocTypeStruct<T>(<T as Mirror>::Image); | |
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25 | |
26 | fn main() { | |
27 | // Functions | |
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28 | assert_eq!(size_of::<fn(isize)>(), size_of::<Option<fn(isize)>>()); |
29 | assert_eq!(size_of::<extern "C" fn(isize)>(), size_of::<Option<extern "C" fn(isize)>>()); | |
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30 | |
31 | // Slices - &str / &[T] / &mut [T] | |
32 | assert_eq!(size_of::<&str>(), size_of::<Option<&str>>()); | |
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33 | assert_eq!(size_of::<&[isize]>(), size_of::<Option<&[isize]>>()); |
34 | assert_eq!(size_of::<&mut [isize]>(), size_of::<Option<&mut [isize]>>()); | |
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35 | |
36 | // Traits - Box<Trait> / &Trait / &mut Trait | |
37 | assert_eq!(size_of::<Box<Trait>>(), size_of::<Option<Box<Trait>>>()); | |
38 | assert_eq!(size_of::<&Trait>(), size_of::<Option<&Trait>>()); | |
39 | assert_eq!(size_of::<&mut Trait>(), size_of::<Option<&mut Trait>>()); | |
40 | ||
41 | // Pointers - Box<T> | |
c34b1796 | 42 | assert_eq!(size_of::<Box<isize>>(), size_of::<Option<Box<isize>>>()); |
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43 | |
44 | // The optimization can't apply to raw pointers | |
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45 | assert!(size_of::<Option<*const isize>>() != size_of::<*const isize>()); |
46 | assert!(Some(0 as *const isize).is_some()); // Can't collapse None to null | |
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47 | |
48 | struct Foo { | |
c34b1796 | 49 | _a: Box<isize> |
1a4d82fc | 50 | } |
c34b1796 | 51 | struct Bar(Box<isize>); |
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52 | |
53 | // Should apply through structs | |
54 | assert_eq!(size_of::<Foo>(), size_of::<Option<Foo>>()); | |
55 | assert_eq!(size_of::<Bar>(), size_of::<Option<Bar>>()); | |
56 | // and tuples | |
c34b1796 | 57 | assert_eq!(size_of::<(u8, Box<isize>)>(), size_of::<Option<(u8, Box<isize>)>>()); |
1a4d82fc | 58 | // and fixed-size arrays |
c34b1796 | 59 | assert_eq!(size_of::<[Box<isize>; 1]>(), size_of::<Option<[Box<isize>; 1]>>()); |
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60 | |
61 | // Should apply to NonZero | |
c34b1796 | 62 | assert_eq!(size_of::<NonZero<usize>>(), size_of::<Option<NonZero<usize>>>()); |
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63 | assert_eq!(size_of::<NonZero<*mut i8>>(), size_of::<Option<NonZero<*mut i8>>>()); |
64 | ||
65 | // Should apply to types that use NonZero internally | |
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66 | assert_eq!(size_of::<Vec<isize>>(), size_of::<Option<Vec<isize>>>()); |
67 | assert_eq!(size_of::<Arc<isize>>(), size_of::<Option<Arc<isize>>>()); | |
68 | assert_eq!(size_of::<Rc<isize>>(), size_of::<Option<Rc<isize>>>()); | |
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69 | |
70 | // Should apply to types that have NonZero transitively | |
71 | assert_eq!(size_of::<String>(), size_of::<Option<String>>()); | |
72 | ||
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73 | // Should apply to types where the pointer is substituted |
74 | assert_eq!(size_of::<&u8>(), size_of::<Option<ParamTypeStruct<&u8>>>()); | |
75 | assert_eq!(size_of::<&u8>(), size_of::<Option<AssocTypeStruct<&u8>>>()); | |
1a4d82fc | 76 | } |