25 lines
697 B
Rust
25 lines
697 B
Rust
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// Regression test for #82612.
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use std::marker::PhantomData;
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pub trait SparseSetIndex {
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fn sparse_set_index(&self) -> usize;
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}
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pub struct SparseArray<I, V = I> {
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values: Vec<Option<V>>,
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marker: PhantomData<I>,
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}
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impl<I: SparseSetIndex, V> SparseArray<I, V> {
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pub fn get_or_insert_with(&mut self, index: I, func: impl FnOnce() -> V) -> &mut V {
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let index = index.sparse_set_index();
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if index < self.values.len() {
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let value = unsafe { self.values.get_unchecked_mut(index) };
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value.get_or_insert_with(func) //~ ERROR mismatched types
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}
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unsafe { self.values.get_unchecked_mut(index).as_mut().unwrap() }
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}
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}
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fn main() {}
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