Fix clippy warnings

Author: Amanieu

src/map.rs

@@ -6718,7 +6718,6 @@ mod test_map {
     use rand::{rngs::SmallRng, Rng, SeedableRng};
     use std::borrow::ToOwned;
     use std::cell::RefCell;
-    use std::usize;
     use std::vec::Vec;
 
     #[test]

src/raw/mod.rs

@@ -1235,7 +1235,7 @@ impl<T, A: Allocator> RawTable<T, A> {
                 fallibility,
                 Self::TABLE_LAYOUT,
                 if T::NEEDS_DROP {
-                    Some(mem::transmute(ptr::drop_in_place::<T> as unsafe fn(*mut T)))
+                    Some(|ptr| ptr::drop_in_place(ptr as *mut T))
                 } else {
                     None
                 },
@@ -2911,7 +2911,7 @@ impl RawTableInner {
         hasher: &dyn Fn(&mut Self, usize) -> u64,
         fallibility: Fallibility,
         layout: TableLayout,
-        drop: Option<fn(*mut u8)>,
+        drop: Option<unsafe fn(*mut u8)>,
     ) -> Result<(), TryReserveError>
     where
         A: Allocator,
@@ -3145,7 +3145,7 @@ impl RawTableInner {
         &mut self,
         hasher: &dyn Fn(&mut Self, usize) -> u64,
         size_of: usize,
-        drop: Option<fn(*mut u8)>,
+        drop: Option<unsafe fn(*mut u8)>,
     ) {
         // If the hash function panics then properly clean up any elements
         // that we haven't rehashed yet. We unfortunately can't preserve the
@@ -4577,7 +4577,7 @@ mod test_map {
                 &|table, index| hasher(table.bucket::<T>(index).as_ref()),
                 mem::size_of::<T>(),
                 if mem::needs_drop::<T>() {
-                    Some(mem::transmute(ptr::drop_in_place::<T> as unsafe fn(*mut T)))
+                    Some(|ptr| ptr::drop_in_place(ptr as *mut T))
                 } else {
                     None
                 },

tests/hasher.rs

@@ -11,13 +11,13 @@ fn check<S: BuildHasher + Default>() {
     let mut set = HashSet::<i32, S>::default();
     set.extend(range.clone());
 
-    assert!(!set.contains(&i32::min_value()));
+    assert!(!set.contains(&i32::MIN));
     assert!(!set.contains(&(range.start - 1)));
     for i in range.clone() {
         assert!(set.contains(&i));
     }
     assert!(!set.contains(&range.end));
-    assert!(!set.contains(&i32::max_value()));
+    assert!(!set.contains(&i32::MAX));
 }
 
 /// Use hashbrown's default hasher.
@@ -56,7 +56,7 @@ fn max() {
 
     impl Hasher for MaxHasher {
         fn finish(&self) -> u64 {
-            u64::max_value()
+            u64::MAX
         }
         fn write(&mut self, _: &[u8]) {}
     }