1 // ignore-tidy-linelength
2 // This test checks that calling `mem::{uninitialized,zeroed}` with certain types results
5 #![feature(never_type, rustc_attrs)]
7 #![deny(invalid_value)]
9 use std::mem::{self, MaybeUninit};
10 use std::num::NonZeroU32;
14 struct Ref(&'static i32);
15 struct RefPair((&'static i32, i32));
17 struct Wrap<T> { wrapped: T }
18 enum WrapEnum<T> { Wrapped(T) }
20 #[rustc_layout_scalar_valid_range_start(0)]
21 #[rustc_layout_scalar_valid_range_end(128)]
23 pub(crate) struct NonBig(u64);
26 fn generic<T: 'static>() {
28 let _val: &'static T = mem::zeroed(); //~ ERROR: does not permit zero-initialization
29 let _val: &'static T = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
31 let _val: Wrap<&'static T> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
32 let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
38 // Things that cannot even be zero.
39 let _val: ! = mem::zeroed(); //~ ERROR: does not permit zero-initialization
40 let _val: ! = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
42 let _val: (i32, !) = mem::zeroed(); //~ ERROR: does not permit zero-initialization
43 let _val: (i32, !) = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
45 let _val: Void = mem::zeroed(); //~ ERROR: does not permit zero-initialization
46 let _val: Void = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
48 let _val: &'static i32 = mem::zeroed(); //~ ERROR: does not permit zero-initialization
49 let _val: &'static i32 = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
51 let _val: Ref = mem::zeroed(); //~ ERROR: does not permit zero-initialization
52 let _val: Ref = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
54 let _val: fn() = mem::zeroed(); //~ ERROR: does not permit zero-initialization
55 let _val: fn() = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
57 let _val: Wrap<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
58 let _val: Wrap<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
60 let _val: WrapEnum<fn()> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
61 let _val: WrapEnum<fn()> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
63 let _val: Wrap<(RefPair, i32)> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
64 let _val: Wrap<(RefPair, i32)> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
66 let _val: Vec<i32> = mem::zeroed(); //~ ERROR: does not permit zero-initialization
67 let _val: Vec<i32> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
69 // Things that can be zero, but not uninit.
70 let _val: bool = mem::zeroed();
71 let _val: bool = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
73 let _val: Wrap<char> = mem::zeroed();
74 let _val: Wrap<char> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
76 let _val: NonBig = mem::zeroed();
77 let _val: NonBig = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
80 let _val: &'static i32 = mem::transmute(0usize); //~ ERROR: does not permit zero-initialization
81 let _val: &'static [i32] = mem::transmute((0usize, 0usize)); //~ ERROR: does not permit zero-initialization
82 let _val: NonZeroU32 = mem::transmute(0); //~ ERROR: does not permit zero-initialization
84 // Some more types that should work just fine.
85 let _val: Option<&'static i32> = mem::zeroed();
86 let _val: Option<fn()> = mem::zeroed();
87 let _val: MaybeUninit<&'static i32> = mem::zeroed();
88 let _val: i32 = mem::zeroed();