1 files changed, 152 insertions, 0 deletions
diff --git a/third_party/rust/bumpalo/src/collections/collect_in.rs b/third_party/rust/bumpalo/src/collections/collect_in.rs
new file mode 100644
index 0000000000..3e1adeaeaa
--- /dev/null
+++ b/third_party/rust/bumpalo/src/collections/collect_in.rs
@@ -0,0 +1,152 @@
+#[cfg(feature = "boxed")]
+use crate::boxed::Box;
+use crate::collections::{String, Vec};
+use crate::Bump;
+
+/// A trait for types that support being constructed from an iterator, parameterized by an allocator.
+pub trait FromIteratorIn<A> {
+    /// The allocator type
+    type Alloc;
+
+    /// Similar to [`FromIterator::from_iter`][from_iter], but with a given allocator.
+    ///
+    /// [from_iter]: https://doc.rust-lang.org/std/iter/trait.FromIterator.html#tymethod.from_iter
+    ///
+    /// ```
+    /// # use bumpalo::collections::{FromIteratorIn, Vec};
+    /// # use bumpalo::Bump;
+    /// #
+    /// let five_fives = std::iter::repeat(5).take(5);
+    /// let bump = Bump::new();
+    ///
+    /// let v = Vec::from_iter_in(five_fives, &bump);
+    ///
+    /// assert_eq!(v, [5, 5, 5, 5, 5]);
+    /// ```
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = A>;
+}
+
+#[cfg(feature = "boxed")]
+impl<'bump, T> FromIteratorIn<T> for Box<'bump, [T]> {
+    type Alloc = &'bump Bump;
+
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = T>,
+    {
+        Box::from_iter_in(iter, alloc)
+    }
+}
+
+impl<'bump, T> FromIteratorIn<T> for Vec<'bump, T> {
+    type Alloc = &'bump Bump;
+
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = T>,
+    {
+        Vec::from_iter_in(iter, alloc)
+    }
+}
+
+impl<T, V: FromIteratorIn<T>> FromIteratorIn<Option<T>> for Option<V> {
+    type Alloc = V::Alloc;
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = Option<T>>,
+    {
+        iter.into_iter()
+            .map(|x| x.ok_or(()))
+            .collect_in::<Result<_, _>>(alloc)
+            .ok()
+    }
+}
+
+impl<T, E, V: FromIteratorIn<T>> FromIteratorIn<Result<T, E>> for Result<V, E> {
+    type Alloc = V::Alloc;
+    /// Takes each element in the `Iterator`: if it is an `Err`, no further
+    /// elements are taken, and the `Err` is returned. Should no `Err` occur, a
+    /// container with the values of each `Result` is returned.
+    ///
+    /// Here is an example which increments every integer in a vector,
+    /// checking for overflow:
+    ///
+    /// ```
+    /// # use bumpalo::collections::{FromIteratorIn, CollectIn, Vec, String};
+    /// # use bumpalo::Bump;
+    /// #
+    /// let bump = Bump::new();
+    ///
+    /// let v = vec![1, 2, u32::MAX];
+    /// let res: Result<Vec<u32>, &'static str> = v.iter().take(2).map(|x: &u32|
+    ///     x.checked_add(1).ok_or("Overflow!")
+    /// ).collect_in(&bump);
+    /// assert_eq!(res, Ok(bumpalo::vec![in &bump; 2, 3]));
+    ///
+    /// let res: Result<Vec<u32>, &'static str> = v.iter().map(|x: &u32|
+    ///     x.checked_add(1).ok_or("Overflow!")
+    /// ).collect_in(&bump);
+    /// assert_eq!(res, Err("Overflow!"));
+    /// ```
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = Result<T, E>>,
+    {
+        let mut iter = iter.into_iter();
+        let mut error = None;
+        let container = core::iter::from_fn(|| match iter.next() {
+            Some(Ok(x)) => Some(x),
+            Some(Err(e)) => {
+                error = Some(e);
+                None
+            }
+            None => None,
+        })
+        .collect_in(alloc);
+
+        match error {
+            Some(e) => Err(e),
+            None => Ok(container),
+        }
+    }
+}
+
+impl<'bump> FromIteratorIn<char> for String<'bump> {
+    type Alloc = &'bump Bump;
+
+    fn from_iter_in<I>(iter: I, alloc: Self::Alloc) -> Self
+    where
+        I: IntoIterator<Item = char>,
+    {
+        String::from_iter_in(iter, alloc)
+    }
+}
+
+/// Extension trait for iterators, in order to allow allocator-parameterized collections to be constructed more easily.
+pub trait CollectIn: Iterator + Sized {
+    /// Collect all items from an iterator, into a collection parameterized by an allocator.
+    /// Similar to [`Iterator::collect`][collect].
+    ///
+    /// [collect]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.collect
+    ///
+    /// ```
+    /// # use bumpalo::collections::{FromIteratorIn, CollectIn, Vec, String};
+    /// # use bumpalo::Bump;
+    /// #
+    /// let bump = Bump::new();
+    ///
+    /// let str = "hello, world!".to_owned();
+    /// let bump_str: String = str.chars().collect_in(&bump);
+    /// assert_eq!(&bump_str, &str);
+    ///
+    /// let nums: Vec<i32> = (0..=3).collect_in::<Vec<_>>(&bump);
+    /// assert_eq!(&nums, &[0,1,2,3]);
+    /// ```
+    fn collect_in<C: FromIteratorIn<Self::Item>>(self, alloc: C::Alloc) -> C {
+        C::from_iter_in(self, alloc)
+    }
+}
+
+impl<I: Iterator> CollectIn for I {}