mirror of https://github.com/rust-lang/rust
36 lines
805 B
Rust
36 lines
805 B
Rust
// rust-lang/rust#60431: This is a scenario where to determine the size of
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// `&Ref<Obstack>`, we need to know the concrete type of the last field in
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// `Ref<Obstack>` (i.e. its "struct tail"), and determining that concrete type
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// requires normalizing `Obstack::Dyn`.
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//
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// The old "struct tail" computation did not perform such normalization, and so
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// the compiler would ICE when trying to figure out if `Ref<Obstack>` is a
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// dynamically-sized type (DST).
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//@ run-pass
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use std::mem;
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pub trait Arena {
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type Dyn : ?Sized;
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}
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pub struct DynRef {
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_dummy: [()],
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}
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pub struct Ref<A: Arena> {
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_value: u8,
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_dyn_arena: A::Dyn,
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}
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pub struct Obstack;
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impl Arena for Obstack {
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type Dyn = DynRef;
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}
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fn main() {
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assert_eq!(mem::size_of::<&Ref<Obstack>>(), mem::size_of::<&[()]>());
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}
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