Auto merge of #60898 - Centril:rollup-76o2g8a, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #60685 (Switch to SPDX 2.1 license expression)
 - #60687 (Fix .natvis visualizers.)
 - #60805 (remove compiletest's dependency on `filetime`)
 - #60862 (Get ty from local_decls instead of using Place)
 - #60873 (Parse alternative incorrect uses of await and recover)
 - #60894 (Add entry-like methods to HashSet)

Failed merges:

r? @ghost

2 files changed, 57 insertions, 1 deletions

diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index ad5d62f667a..5d797b75621 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -3,7 +3,7 @@ authors = ["The Rust Project Developers"]
 name = "std"
 version = "0.0.0"
 build = "build.rs"
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust.git"
 description = "The Rust Standard Library"
 edition = "2018"
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index b56a27c80bc..403914c0707 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -618,6 +618,62 @@ impl<T, S> HashSet<T, S>
         self.map.get_key_value(value).map(|(k, _)| k)
     }
 
+    /// Inserts the given `value` into the set if it is not present, then
+    /// returns a reference to the value in the set.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(hash_set_entry)]
+    ///
+    /// use std::collections::HashSet;
+    ///
+    /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+    /// assert_eq!(set.len(), 3);
+    /// assert_eq!(set.get_or_insert(2), &2);
+    /// assert_eq!(set.get_or_insert(100), &100);
+    /// assert_eq!(set.len(), 4); // 100 was inserted
+    /// ```
+    #[inline]
+    #[unstable(feature = "hash_set_entry", issue = "60896")]
+    pub fn get_or_insert(&mut self, value: T) -> &T {
+        // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with
+        // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`.
+        self.map.raw_entry_mut().from_key(&value).or_insert(value, ()).0
+    }
+
+    /// Inserts a value computed from `f` into the set if the given `value` is
+    /// not present, then returns a reference to the value in the set.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(hash_set_entry)]
+    ///
+    /// use std::collections::HashSet;
+    ///
+    /// let mut set: HashSet<String> = ["cat", "dog", "horse"]
+    ///     .iter().map(|&pet| pet.to_owned()).collect();
+    ///
+    /// assert_eq!(set.len(), 3);
+    /// for &pet in &["cat", "dog", "fish"] {
+    ///     let value = set.get_or_insert_with(pet, str::to_owned);
+    ///     assert_eq!(value, pet);
+    /// }
+    /// assert_eq!(set.len(), 4); // a new "fish" was inserted
+    /// ```
+    #[inline]
+    #[unstable(feature = "hash_set_entry", issue = "60896")]
+    pub fn get_or_insert_with<Q: ?Sized, F>(&mut self, value: &Q, f: F) -> &T
+        where T: Borrow<Q>,
+              Q: Hash + Eq,
+              F: FnOnce(&Q) -> T
+    {
+        // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with
+        // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`.
+        self.map.raw_entry_mut().from_key(value).or_insert_with(|| (f(value), ())).0
+    }
+
     /// Returns `true` if `self` has no elements in common with `other`.
     /// This is equivalent to checking for an empty intersection.
     ///