mirror of https://github.com/rust-lang/rust
18 lines
530 B
Rust
18 lines
530 B
Rust
use std::ops::Index;
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pub trait Array2D: Index<usize> + Sized {
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fn rows(&self) -> usize;
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fn columns(&self) -> usize;
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fn get<'a>(&'a self, y: usize, x: usize) -> Option<&'a <Self as Index<usize>>::Output> {
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if y >= self.rows() || x >= self.columns() {
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return None;
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}
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let i = y * self.columns() + x;
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let indexer = &(*self as &dyn Index<usize, Output = <Self as Index<usize>>::Output>);
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//~^ERROR non-primitive cast
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Some(indexer.index(i))
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}
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}
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fn main() {}
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