Vendor things

third-party/vendor/dashmap/src/setref/multiple.rs

@@ -0,0 +1,25 @@
+use crate::mapref;
+use core::hash::{BuildHasher, Hash};
+use core::ops::Deref;
+use std::collections::hash_map::RandomState;
+pub struct RefMulti<'a, K, S = RandomState> {
+    inner: mapref::multiple::RefMulti<'a, K, (), S>,
+}
+
+impl<'a, K: Eq + Hash, S: BuildHasher> RefMulti<'a, K, S> {
+    pub(crate) fn new(inner: mapref::multiple::RefMulti<'a, K, (), S>) -> Self {
+        Self { inner }
+    }
+
+    pub fn key(&self) -> &K {
+        self.inner.key()
+    }
+}
+
+impl<'a, K: Eq + Hash, S: BuildHasher> Deref for RefMulti<'a, K, S> {
+    type Target = K;
+
+    fn deref(&self) -> &K {
+        self.key()
+    }
+}