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btree: cleanup difference, intersection, is_subset #147808

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179 changes: 86 additions & 93 deletions library/alloc/src/collections/btree/set.rs
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Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
where
T: Ord,
{
let (self_min, self_max) =
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
(self_min, self_max)
} else {
return Difference { inner: DifferenceInner::Iterate(self.iter()) };
};
let (other_min, other_max) =
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
(other_min, other_max)
} else {
return Difference { inner: DifferenceInner::Iterate(self.iter()) };
};
Difference {
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
(Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
(Equal, _) => {
let mut self_iter = self.iter();
self_iter.next();
DifferenceInner::Iterate(self_iter)
}
(_, Equal) => {
let mut self_iter = self.iter();
self_iter.next_back();
DifferenceInner::Iterate(self_iter)
}
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
DifferenceInner::Search { self_iter: self.iter(), other_set: other }
}
_ => DifferenceInner::Stitch {
self_iter: self.iter(),
other_iter: other.iter().peekable(),
if let Some(self_min) = self.first()
&& let Some(self_max) = self.last()
&& let Some(other_min) = other.first()
&& let Some(other_max) = other.last()
{
Difference {
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
(Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
(Equal, _) => {
let mut self_iter = self.iter();
self_iter.next();
DifferenceInner::Iterate(self_iter)
}
(_, Equal) => {
let mut self_iter = self.iter();
self_iter.next_back();
DifferenceInner::Iterate(self_iter)
}
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
DifferenceInner::Search { self_iter: self.iter(), other_set: other }
}
_ => DifferenceInner::Stitch {
self_iter: self.iter(),
other_iter: other.iter().peekable(),
},
},
},
}
} else {
Difference { inner: DifferenceInner::Iterate(self.iter()) }
}
}

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
where
T: Ord,
{
let (self_min, self_max) =
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
(self_min, self_max)
} else {
return Intersection { inner: IntersectionInner::Answer(None) };
};
let (other_min, other_max) =
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
(other_min, other_max)
} else {
return Intersection { inner: IntersectionInner::Answer(None) };
};
Intersection {
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
(Greater, _) | (_, Less) => IntersectionInner::Answer(None),
(Equal, _) => IntersectionInner::Answer(Some(self_min)),
(_, Equal) => IntersectionInner::Answer(Some(self_max)),
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
IntersectionInner::Search { small_iter: self.iter(), large_set: other }
}
_ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
IntersectionInner::Search { small_iter: other.iter(), large_set: self }
}
_ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
},
if let Some(self_min) = self.first()
&& let Some(self_max) = self.last()
&& let Some(other_min) = other.first()
&& let Some(other_max) = other.last()
{
Intersection {
inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
(Greater, _) | (_, Less) => IntersectionInner::Answer(None),
(Equal, _) => IntersectionInner::Answer(Some(self_min)),
(_, Equal) => IntersectionInner::Answer(Some(self_max)),
_ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
IntersectionInner::Search { small_iter: self.iter(), large_set: other }
}
_ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
IntersectionInner::Search { small_iter: other.iter(), large_set: self }
}
_ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
},
}
} else {
Intersection { inner: IntersectionInner::Answer(None) }
}
}

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
// Same result as self.difference(other).next().is_none()
// but the code below is faster (hugely in some cases).
if self.len() > other.len() {
return false;
return false; // self has more elements than other
}
let (self_min, self_max) =
if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
(self_min, self_max)
} else {
return true; // self is empty
};
let (other_min, other_max) =
if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
(other_min, other_max)
} else {
return false; // other is empty
};
let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
return true; // self is empty
};
let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
return false; // other is empty
};
let mut self_iter = self.iter();
match self_min.cmp(other_min) {
Less => return false,
Less => return false, // other does not contain self_min
Equal => {
self_iter.next();
self_iter.next(); // self_min is contained in other, so remove it from consideration
// other_min is now not in self_iter (used below)
}
Greater => (),
}
Greater => {} // other_min is not in self_iter (used below)
};

match self_max.cmp(other_max) {
Greater => return false,
Greater => return false, // other does not contain self_max
Equal => {
self_iter.next_back();
self_iter.next_back(); // self_max is contained in other, so remove it from consideration
// other_max is now not in self_iter (used below)
}
Less => (),
}
Less => {} // other_max is not in self_iter (used below)
};
if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
for next in self_iter {
if !other.contains(next) {
return false;
}
}
self_iter.all(|e| other.contains(e))
} else {
let mut other_iter = other.iter();
other_iter.next();
other_iter.next_back();
let mut self_next = self_iter.next();
while let Some(self1) = self_next {
match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
Less => return false,
Equal => self_next = self_iter.next(),
Greater => (),
}
{
// remove other_min and other_max as they are not in self_iter (see above)
other_iter.next();
other_iter.next_back();
}
// custom `self_iter.all(|e| other.contains(e))`
self_iter.all(|self1| {
while let Some(other1) = other_iter.next() {
match other1.cmp(self1) {
// happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
Less => continue, // skip over elements that are smaller
// happens `self.len()` times
Equal => return true, // self1 is in other
// happens only once
Greater => return false, // self1 is not in other
}
}
false
})
}
true
}

/// Returns `true` if the set is a superset of another,
Expand Down
2 changes: 1 addition & 1 deletion library/alloctests/Cargo.toml
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down
2 changes: 1 addition & 1 deletion tests/run-make/alloc-no-oom-handling/rmake.rs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
rustc()
.edition("2021")
.edition("2024")
.arg("-Dwarnings")
.crate_type("rlib")
.input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
2 changes: 1 addition & 1 deletion tests/run-make/alloc-no-rc/rmake.rs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
rustc()
.edition("2021")
.edition("2024")
.arg("-Dwarnings")
.crate_type("rlib")
.input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
2 changes: 1 addition & 1 deletion tests/run-make/alloc-no-sync/rmake.rs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
rustc()
.edition("2021")
.edition("2024")
.arg("-Dwarnings")
.crate_type("rlib")
.input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
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btree: cleanup difference, intersection, is_subset#147808

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 Merged

bors
merged 1 commit into

from

Nov 7, 2025
 Merged


btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
Skip to content
btree: cleanup difference, intersection, is_subset#147808

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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to your account

 Merged

bors
merged 1 commit into

from

Nov 7, 2025
 Merged


btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
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btree: cleanup difference, intersection, is_subset#147808

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btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
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var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
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return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
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var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
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});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
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try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
Skip to content
btree: cleanup difference, intersection, is_subset#147808

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 Merged

bors
merged 1 commit into

from

Nov 7, 2025
 Merged


btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
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if (location.href !== lastUrl) {
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observer.observe(document.body, { childList: true, subtree: true });
})();
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} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
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btree: cleanup difference, intersection, is_subset#147808

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btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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// Remove or un-stick sticky/fixed headers that block content
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document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
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(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
Skip to content
btree: cleanup difference, intersection, is_subset#147808

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 Merged

bors
merged 1 commit into

from

Nov 7, 2025
 Merged


btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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if (__m === '*' || __re.test(location.href)) {
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img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
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filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
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::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
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/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
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enabled = !enabled;
if (enabled) {
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console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
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// Apply on load
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// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
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} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
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btree: cleanup difference, intersection, is_subset by hkBst · Pull Request #147808 · rust-lang/rust · GitHub
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Nov 7, 2025
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btree: cleanup difference, intersection, is_subset
#147808
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179 changes: 86 additions & 93 deletions
library/alloc/src/collections/btree/set.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -427,39 +427,35 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Difference { inner: DifferenceInner::Iterate(self.iter()) };
 };
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Difference {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()),
 (Equal, _) => {
 let mut self_iter = self.iter();
 self_iter.next();
 DifferenceInner::Iterate(self_iter)
 }
 (_, Equal) => {
 let mut self_iter = self.iter();
 self_iter.next_back();
 DifferenceInner::Iterate(self_iter)
 }
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 DifferenceInner::Search { self_iter: self.iter(), other_set: other }
 }
 _ => DifferenceInner::Stitch {
 self_iter: self.iter(),
 other_iter: other.iter().peekable(),
 },
 },
 },
 }
 } else {
 Difference { inner: DifferenceInner::Iterate(self.iter()) }
 }
 }

Expand DownExpand Up@@ -519,31 +515,27 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 where
 T: Ord,
 {
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return Intersection { inner: IntersectionInner::Answer(None) };
 };
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 if let Some(self_min) = self.first()
 && let Some(self_max) = self.last()
 && let Some(other_min) = other.first()
 && let Some(other_max) = other.last()
 {
 Intersection {
 inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) {
 (Greater, _) | (_, Less) => IntersectionInner::Answer(None),
 (Equal, _) => IntersectionInner::Answer(Some(self_min)),
 (_, Equal) => IntersectionInner::Answer(Some(self_max)),
 _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: self.iter(), large_set: other }
 }
 _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => {
 IntersectionInner::Search { small_iter: other.iter(), large_set: self }
 }
 _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() },
 },
 }
 } else {
 Intersection { inner: IntersectionInner::Answer(None) }
 }
 }

Expand DownExpand Up@@ -694,55 +686,56 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
 // Same result as self.difference(other).next().is_none()
 // but the code below is faster (hugely in some cases).
 if self.len() > other.len() {
 return false;
 return false; // self has more elements than other
 }
 let (self_min, self_max) =
 if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) {
 (self_min, self_max)
 } else {
 return true; // self is empty
 };
 let (other_min, other_max) =
 if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) {
 (other_min, other_max)
 } else {
 return false; // other is empty
 };
 let (Some(self_min), Some(self_max)) = (self.first(), self.last()) else {
 return true; // self is empty
 };
 let (Some(other_min), Some(other_max)) = (other.first(), other.last()) else {
 return false; // other is empty
 };
 let mut self_iter = self.iter();
 match self_min.cmp(other_min) {
 Less => return false,
 Less => return false, // other does not contain self_min
 Equal => {
 self_iter.next();
 self_iter.next(); // self_min is contained in other, so remove it from consideration
 // other_min is now not in self_iter (used below)
 }
 Greater => (),
 }
 Greater => {} // other_min is not in self_iter (used below)
 };

 match self_max.cmp(other_max) {
 Greater => return false,
 Greater => return false, // other does not contain self_max
 Equal => {
 self_iter.next_back();
 self_iter.next_back(); // self_max is contained in other, so remove it from consideration
 // other_max is now not in self_iter (used below)
 }
 Less => (),
 }
 Less => {} // other_max is not in self_iter (used below)
 };
 if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF {
 for next in self_iter {
 if !other.contains(next) {
 return false;
 }
 }
 self_iter.all(|e| other.contains(e))
 } else {
 let mut other_iter = other.iter();
 other_iter.next();
 other_iter.next_back();
 let mut self_next = self_iter.next();
 while let Some(self1) = self_next {
 match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) {
 Less => return false,
 Equal => self_next = self_iter.next(),
 Greater => (),
 }
 {
 // remove other_min and other_max as they are not in self_iter (see above)
 other_iter.next();
 other_iter.next_back();
 }
 // custom `self_iter.all(|e| other.contains(e))`
 self_iter.all(|self1| {
 while let Some(other1) = other_iter.next() {
 match other1.cmp(self1) {
 // happens up to `ITER_PERFORMANCE_TIPPING_SIZE_DIFF * self.len() - 1` times
 Less => continue, // skip over elements that are smaller
 // happens `self.len()` times
 Equal => return true, // self1 is in other
 // happens only once
 Greater => return false, // self1 is not in other
 }
 }
 false
 })
 }
 true
 }

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

2 changes: 1 addition & 1 deletion
library/alloctests/Cargo.toml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ repository = "https://github.com/rust-lang/rust.git"
description = "Tests for the Rust Allocation Library"
autotests = false
autobenches = false
edition = "2021"
edition = "2024"

[lib]
path = "lib.rs"
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-oom-handling/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-rc/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down

2 changes: 1 addition & 1 deletion
tests/run-make/alloc-no-sync/rmake.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6,7 +6,7 @@ use run_make_support::{rustc, source_root};

fn main() {
 rustc()
 .edition("2021")
 .edition("2024")
 .arg("-Dwarnings")
 .crate_type("rlib")
 .input(source_root().join("library/alloc/src/lib.rs"))
Expand Down
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