44 lines
1.2 KiB
Rust
44 lines
1.2 KiB
Rust
// check-pass
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//! The presence of an `align(X)` annotation must be accounted for.
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#![crate_type = "lib"]
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#![feature(transmutability)]
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#![allow(dead_code, incomplete_features, non_camel_case_types)]
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mod assert {
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use std::mem::{Assume, BikeshedIntrinsicFrom};
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pub struct Context;
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pub fn is_maybe_transmutable<Src, Dst>()
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where
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Dst: BikeshedIntrinsicFrom<Src, Context, {
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Assume {
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alignment: true,
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lifetimes: true,
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safety: true,
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validity: true,
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}
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}>
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{}
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}
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fn should_pad_explicitly_aligned_field() {
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#[derive(Clone, Copy)] #[repr(u8)] enum V0u8 { V = 0 }
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#[repr(C)]
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pub union Uninit {
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a: (),
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b: V0u8,
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}
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#[repr(C, align(2))] struct align_2(V0u8);
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#[repr(C)] struct ImplicitlyPadded(align_2, V0u8);
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#[repr(C)] struct ExplicitlyPadded(V0u8, Uninit, V0u8);
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// An implementation that (incorrectly) does not place a padding byte after
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// `align_2` will, incorrectly, reject the following transmutations.
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assert::is_maybe_transmutable::<ImplicitlyPadded, ExplicitlyPadded>();
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assert::is_maybe_transmutable::<ExplicitlyPadded, ImplicitlyPadded>();
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}
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