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https://github.com/rust-lang/rust
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20 lines
423 B
Rust
20 lines
423 B
Rust
#![feature(rustc_attrs)]
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#[rustc_layout_scalar_valid_range_start(1)]
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#[repr(transparent)]
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pub(crate) struct NonZero<T>(pub(crate) T);
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fn main() {}
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const fn foo() -> NonZero<u32> {
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let mut x = unsafe { NonZero(1) };
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x.0 = 0;
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//~^ ERROR mutation of layout constrained field is unsafe
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x
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}
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const fn bar() -> NonZero<u32> {
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let mut x = unsafe { NonZero(1) };
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unsafe { x.0 = 0 }; // this is UB
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x
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}
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