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5c04151c6c
Implementing `PointerLike` for `UnsafeCell` enables the possibility of interior mutable `dyn*` values. Since this means potentially exercising new codegen behavior, I added a test for it in `tests/ui/dyn-star/cell.rs`. Also updated UI tests to account for the `isize` implementation changing error messages.
35 lines
577 B
Rust
35 lines
577 B
Rust
// This test with Cell also indirectly exercises UnsafeCell in dyn*.
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//
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//@ run-pass
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#![feature(dyn_star)]
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#![allow(incomplete_features)]
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use std::cell::Cell;
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trait Rw<T> {
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fn read(&self) -> T;
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fn write(&self, v: T);
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}
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impl<T: Copy> Rw<T> for Cell<T> {
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fn read(&self) -> T {
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self.get()
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}
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fn write(&self, v: T) {
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self.set(v)
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}
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}
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fn make_dyn_star() -> dyn* Rw<usize> {
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Cell::new(42usize) as dyn* Rw<usize>
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}
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fn main() {
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let x = make_dyn_star();
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assert_eq!(x.read(), 42);
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x.write(24);
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assert_eq!(x.read(), 24);
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}
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