41 lines
1.1 KiB
Markdown
41 lines
1.1 KiB
Markdown
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% Deref
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Alright! We've got a decent minimal ArrayStack implemented. We can push, we can
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pop, and we can clean up after ourselves. However there's a whole mess of functionality
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we'd reasonably want. In particular, we have a proper array, but none of the slice
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functionality. That's actually pretty easy to solve: we can implement `Deref<Target=[T]>`.
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This will magically make our Vec coerce to and behave like a slice in all sorts of
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conditions.
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All we need is `slice::from_raw_parts`.
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```rust
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use std::ops::Deref;
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impl<T> Deref for Vec<T> {
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type Target = [T];
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fn deref(&self) -> &[T] {
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unsafe {
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::std::slice::from_raw_parts(*self.ptr, self.len)
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}
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}
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}
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```
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And let's do DerefMut too:
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```rust
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use std::ops::DerefMut;
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impl<T> DerefMut for Vec<T> {
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fn deref_mut(&mut self) -> &mut [T] {
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unsafe {
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::std::slice::from_raw_parts_mut(*self.ptr, self.len)
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}
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}
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}
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```
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Now we have `len`, `first`, `last`, indexing, slicing, sorting, `iter`, `iter_mut`,
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and all other sorts of bells and whistles provided by slice. Sweet!
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