priority_queue: avoid copy with top and maybe_top
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@ -8,10 +8,10 @@ pub struct PriorityQueue <T: Copy Ord>{
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impl <T: Copy Ord> PriorityQueue<T> {
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/// Returns the greatest item in the queue - fails if empty
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pure fn top(&self) -> T { self.data[0] }
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pure fn top(&self) -> &self/T { &self.data[0] }
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/// Returns the greatest item in the queue - None if empty
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pure fn maybe_top(&self) -> Option<T> {
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pure fn maybe_top(&self) -> Option<&self/T> {
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if self.is_empty() { None } else { Some(self.top()) }
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}
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@ -151,7 +151,7 @@ mod tests {
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let mut sorted = merge_sort(data, le);
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let mut heap = from_vec(data);
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while heap.is_not_empty() {
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assert heap.top() == sorted.last();
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assert *heap.top() == sorted.last();
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assert heap.pop() == sorted.pop();
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}
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}
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@ -160,22 +160,22 @@ mod tests {
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fn test_push() {
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let mut heap = from_vec(~[2, 4, 9]);
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assert heap.len() == 3;
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assert heap.top() == 9;
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assert *heap.top() == 9;
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heap.push(11);
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assert heap.len() == 4;
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assert heap.top() == 11;
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assert *heap.top() == 11;
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heap.push(5);
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assert heap.len() == 5;
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assert heap.top() == 11;
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assert *heap.top() == 11;
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heap.push(27);
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assert heap.len() == 6;
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assert heap.top() == 27;
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assert *heap.top() == 27;
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heap.push(3);
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assert heap.len() == 7;
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assert heap.top() == 27;
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assert *heap.top() == 27;
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heap.push(103);
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assert heap.len() == 8;
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assert heap.top() == 103;
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assert *heap.top() == 103;
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}
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#[test]
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@ -241,11 +241,12 @@ mod tests {
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#[test]
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#[should_fail]
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fn test_empty_top() { from_vec::<int>(~[]).top(); }
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fn test_empty_top() { let empty = from_vec::<int>(~[]); empty.top(); }
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#[test]
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fn test_empty_maybe_top() {
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assert from_vec::<int>(~[]).maybe_top().is_none();
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let empty = from_vec::<int>(~[]);
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assert empty.maybe_top().is_none();
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}
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#[test]
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