mirror of https://github.com/rust-lang/rust
20 lines
561 B
Rust
20 lines
561 B
Rust
#![feature(rustc_attrs)]
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use std::cell::Cell;
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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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let mut x = unsafe { NonZero(Cell::new(1)) };
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match x {
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NonZero(ref x) => { x }
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//~^ ERROR borrow of layout constrained field with interior mutability
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};
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let mut y = unsafe { NonZero(42) };
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match y { NonZero(ref y) => { y } }; // OK, type of `y` is freeze
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match y { NonZero(ref mut y) => { y } };
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//~^ ERROR mutation of layout constrained field
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}
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