57 lines
1.4 KiB
Rust
57 lines
1.4 KiB
Rust
|
// revisions: mirunsafeck thirunsafeck
|
||
|
|
// [thirunsafeck]compile-flags: -Z thir-unsafeck
|
||
|
|
|
||
|
|
#![feature(rustc_attrs)]
|
||
|
|
#![allow(unused,dead_code)]
|
||
|
|
|
||
|
|
fn tuple_struct() {
|
||
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
||
|
|
struct NonZero<T>(T);
|
||
|
|
|
||
|
|
let mut foo = unsafe { NonZero((1,)) };
|
||
|
|
let a = &mut foo.0.0;
|
||
|
|
//~^ ERROR: mutation of layout constrained field is unsafe
|
||
|
|
}
|
||
|
|
|
||
|
|
fn slice() {
|
||
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
||
|
|
struct NonZero<'a, T>(&'a mut [T]);
|
||
|
|
|
||
|
|
let mut nums = [1, 2, 3, 4];
|
||
|
|
let mut foo = unsafe { NonZero(&mut nums[..]) };
|
||
|
|
let a = &mut foo.0[2];
|
||
|
|
// ^ not unsafe because there is an implicit dereference here
|
||
|
|
}
|
||
|
|
|
||
|
|
fn array() {
|
||
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
||
|
|
struct NonZero<T>([T; 4]);
|
||
|
|
|
||
|
|
let nums = [1, 2, 3, 4];
|
||
|
|
let mut foo = unsafe { NonZero(nums) };
|
||
|
|
let a = &mut foo.0[2];
|
||
|
|
//~^ ERROR: mutation of layout constrained field is unsafe
|
||
|
|
}
|
||
|
|
|
||
|
|
fn block() {
|
||
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
||
|
|
struct NonZero<T>(T);
|
||
|
|
|
||
|
|
let foo = unsafe { NonZero((1,)) };
|
||
|
|
&mut { foo.0 }.0;
|
||
|
|
// ^ not unsafe because the result of the block expression is a new place
|
||
|
|
}
|
||
|
|
|
||
|
|
fn mtch() {
|
||
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
||
|
|
struct NonZero<T>(T);
|
||
|
|
|
||
|
|
let mut foo = unsafe { NonZero((1,)) };
|
||
|
|
match &mut foo {
|
||
|
|
NonZero((a,)) => *a = 0,
|
||
|
|
//~^ ERROR: mutation of layout constrained field is unsafe
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {}
|