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rust-timerrust-timer
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Unrolled build for #147808
Rollup merge of #147808 - hkBst:btree-3, r=joboet btree: cleanup difference, intersection, is_subset
2 parents c90bcb9 + acd0294 commit 5c3d327

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+87
-94
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2 files changed

+87
-94
lines changed

‎library/alloc/src/collections/btree/set.rs‎

Lines changed: 86 additions & 93 deletions
Original file line numberDiff line numberDiff line change
@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
427427
where
428428
T: Ord,
429429
{
430-
let (self_min, self_max) =
431-
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
432-
(self_min, self_max)
433-
} else {
434-
return Difference { inner: DifferenceInner::Iterate(self.iter()) };
435-
};
436-
let (other_min, other_max) =
437-
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
438-
(other_min, other_max)
439-
} else {
440-
return Difference { inner: DifferenceInner::Iterate(self.iter()) };
441-
};
442-
Difference {
443-
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
444-
(Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
445-
(Equal, _) => {
446-
let mut self_iter = self.iter();
447-
self_iter.next();
448-
DifferenceInner::Iterate(self_iter)
449-
}
450-
(_, Equal) => {
451-
let mut self_iter = self.iter();
452-
self_iter.next_back();
453-
DifferenceInner::Iterate(self_iter)
454-
}
455-
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
456-
DifferenceInner::Search { self_iter: self.iter(), other_set: other }
457-
}
458-
_ => DifferenceInner::Stitch {
459-
self_iter: self.iter(),
460-
other_iter: other.iter().peekable(),
430+
if let Some(self_min) = self.first()
431+
&& let Some(self_max) = self.last()
432+
&& let Some(other_min) = other.first()
433+
&& let Some(other_max) = other.last()
434+
{
435+
Difference {
436+
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
437+
(Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
438+
(Equal, _) => {
439+
let mut self_iter = self.iter();
440+
self_iter.next();
441+
DifferenceInner::Iterate(self_iter)
442+
}
443+
(_, Equal) => {
444+
let mut self_iter = self.iter();
445+
self_iter.next_back();
446+
DifferenceInner::Iterate(self_iter)
447+
}
448+
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
449+
DifferenceInner::Search { self_iter: self.iter(), other_set: other }
450+
}
451+
_ => DifferenceInner::Stitch {
452+
self_iter: self.iter(),
453+
other_iter: other.iter().peekable(),
454+
},
461455
},
462-
},
456+
}
457+
} else {
458+
Difference { inner: DifferenceInner::Iterate(self.iter()) }
463459
}
464460
}
465461

@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
519515
where
520516
T: Ord,
521517
{
522-
let (self_min, self_max) =
523-
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
524-
(self_min, self_max)
525-
} else {
526-
return Intersection { inner: IntersectionInner::Answer(None) };
527-
};
528-
let (other_min, other_max) =
529-
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
530-
(other_min, other_max)
531-
} else {
532-
return Intersection { inner: IntersectionInner::Answer(None) };
533-
};
534-
Intersection {
535-
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
536-
(Greater, _) | (_, Less) => IntersectionInner::Answer(None),
537-
(Equal, _) => IntersectionInner::Answer(Some(self_min)),
538-
(_, Equal) => IntersectionInner::Answer(Some(self_max)),
539-
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
540-
IntersectionInner::Search { small_iter: self.iter(), large_set: other }
541-
}
542-
_ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
543-
IntersectionInner::Search { small_iter: other.iter(), large_set: self }
544-
}
545-
_ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
546-
},
518+
if let Some(self_min) = self.first()
519+
&& let Some(self_max) = self.last()
520+
&& let Some(other_min) = other.first()
521+
&& let Some(other_max) = other.last()
522+
{
523+
Intersection {
524+
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
525+
(Greater, _) | (_, Less) => IntersectionInner::Answer(None),
526+
(Equal, _) => IntersectionInner::Answer(Some(self_min)),
527+
(_, Equal) => IntersectionInner::Answer(Some(self_max)),
528+
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
529+
IntersectionInner::Search { small_iter: self.iter(), large_set: other }
530+
}
531+
_ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
532+
IntersectionInner::Search { small_iter: other.iter(), large_set: self }
533+
}
534+
_ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
535+
},
536+
}
537+
} else {
538+
Intersection { inner: IntersectionInner::Answer(None) }
547539
}
548540
}
549541

@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
694686
// Same result as self.difference(other).next().is_none()
695687
// but the code below is faster (hugely in some cases).
696688
if self.len() > other.len() {
697-
return false;
689+
return false; // self has more elements than other
698690
}
699-
let (self_min, self_max) =
700-
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
701-
(self_min, self_max)
702-
} else {
703-
return true; // self is empty
704-
};
705-
let (other_min, other_max) =
706-
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
707-
(other_min, other_max)
708-
} else {
709-
return false; // other is empty
710-
};
691+
let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
692+
return true; // self is empty
693+
};
694+
let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
695+
return false; // other is empty
696+
};
711697
let mut self_iter = self.iter();
712698
match self_min.cmp(other_min) {
713-
Less => return false,
699+
Less => return false, // other does not contain self_min
714700
Equal => {
715-
self_iter.next();
701+
self_iter.next(); // self_min is contained in other, so remove it from consideration
702+
// other_min is now not in self_iter (used below)
716703
}
717-
Greater => (),
718-
}
704+
Greater => {} // other_min is not in self_iter (used below)
705+
};
706+
719707
match self_max.cmp(other_max) {
720-
Greater => return false,
708+
Greater => return false, // other does not contain self_max
721709
Equal => {
722-
self_iter.next_back();
710+
self_iter.next_back(); // self_max is contained in other, so remove it from consideration
711+
// other_max is now not in self_iter (used below)
723712
}
724-
Less => (),
725-
}
713+
Less => {} // other_max is not in self_iter (used below)
714+
};
726715
if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
727-
for next in self_iter {
728-
if !other.contains(next) {
729-
return false;
730-
}
731-
}
716+
self_iter.all(|e| other.contains(e))
732717
} else {
733718
let mut other_iter = other.iter();
734-
other_iter.next();
735-
other_iter.next_back();
736-
let mut self_next = self_iter.next();
737-
while let Some(self1) = self_next {
738-
match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
739-
Less => return false,
740-
Equal => self_next = self_iter.next(),
741-
Greater => (),
742-
}
719+
{
720+
// remove other_min and other_max as they are not in self_iter (see above)
721+
other_iter.next();
722+
other_iter.next_back();
743723
}
724+
// custom `self_iter.all(|e| other.contains(e))`
725+
self_iter.all(|self1| {
726+
while let Some(other1) = other_iter.next() {
727+
match other1.cmp(self1) {
728+
// happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
729+
Less => continue, // skip over elements that are smaller
730+
// happens `self.len()` times
731+
Equal => return true, // self1 is in other
732+
// happens only once
733+
Greater => return false, // self1 is not in other
734+
}
735+
}
736+
false
737+
})
744738
}
745-
true
746739
}
747740

748741
/// Returns `true` if the set is a superset of another,

‎library/alloctests/Cargo.toml‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
66
description = "Tests for the Rust Allocation Library"
77
autotests = false
88
autobenches = false
9-
edition = "2021"
9+
edition = "2024"
1010

1111
[lib]
1212
path = "lib.rs"

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