44 lines
1009 B
Rust
44 lines
1009 B
Rust
/// intentionally does not implement copy or clone
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/// which should make it harder to misuse;
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/// the idea is to generally try to guarantee all IDs
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/// point to something valid, although duplicate
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/// gets around this if needed
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#[derive(Eq, Hash, PartialEq, Debug)]
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pub struct ID(usize);
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#[derive(Default)]
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pub struct IDTracker {
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free: Vec<ID>,
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cur: usize,
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}
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impl IDTracker {
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pub fn new() -> Self {
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Self::default()
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}
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#[allow(clippy::should_implement_trait)]
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pub fn next(&mut self) -> ID {
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if let Some(id) = self.free.pop() {
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return id;
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}
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let id = ID(self.cur);
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self.cur += 1;
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id
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}
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pub fn free(&mut self, id: ID) {
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self.free.push(id);
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}
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}
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impl ID {
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/// this must be used carefully to make sure
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/// all IDs are still valid references;
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/// named weirdly to indicate this.
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/// generally should not be used in "user" code
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pub fn duplicate(&self) -> Self {
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Self(self.0)
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}
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}
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