Golf

Author: saethlin

library/alloc/src/raw_vec.rs

@@ -4,7 +4,7 @@ use core::alloc::LayoutError;
 use core::cmp;
 use core::hint;
 use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
-use core::ptr::{self, Alignment, NonNull, Unique};
+use core::ptr::{self, NonNull, Unique};
 
 #[cfg(not(no_global_oom_handling))]
 use crate::alloc::handle_alloc_error;
@@ -297,7 +297,20 @@ impl<T, A: Allocator> RawVec<T, A> {
     }
 
     fn current_memory(&self) -> Option<(NonNull<u8>, Layout)> {
-        if T::IS_ZST || self.cap.0 == 0 {
+        // Reduce the amount of code we need to monomorphize per `T`.
+        #[inline]
+        #[rustc_no_mir_inline]
+        unsafe fn inner(size: usize, align: usize, cap: usize) -> Layout {
+            // SAFETY: Precondition guaranteed by the caller
+            unsafe {
+                let size = size.unchecked_mul(cap);
+                Layout::from_size_align_unchecked(size, align)
+            }
+        }
+
+        let cap = self.cap.0;
+
+        if T::IS_ZST || cap == 0 {
             None
         } else {
             // We could use Layout::array here which ensures the absence of isize and usize overflows
@@ -306,10 +319,8 @@ impl<T, A: Allocator> RawVec<T, A> {
             // support such types. So we can do better by skipping some checks and avoid an unwrap.
             const { assert!(mem::size_of::<T>() % mem::align_of::<T>() == 0) };
             unsafe {
-                let align = Alignment::of::<T>();
-                let size = mem::size_of::<T>().unchecked_mul(self.cap.0);
-                let layout = Layout::from_size_alignment(size, align).unwrap_unchecked();
-                Some((self.ptr.cast().into(), layout))
+                let layout = inner(mem::size_of::<T>(), mem::align_of::<T>(), cap);
+                Some((self.non_null().cast(), layout))
             }
         }
     }

library/core/src/alloc/layout.rs

@@ -97,10 +97,8 @@ impl Layout {
     }
 
     /// Internal helper constructor to skip revalidating alignment validity.
-    #[unstable(feature = "ptr_alignment_type", issue = "102070")]
-    #[rustc_const_unstable(feature = "ptr_alignment_type", issue = "102070")]
     #[inline]
-    pub const fn from_size_alignment(size: usize, align: Alignment) -> Result<Self, LayoutError> {
+    const fn from_size_alignment(size: usize, align: Alignment) -> Result<Self, LayoutError> {
         if size > Self::max_size_for_align(align) {
             return Err(LayoutError);
         }

library/core/src/result.rs

@@ -1481,6 +1481,7 @@ impl<T, E> Result<T, E> {
     #[track_caller]
     #[stable(feature = "option_result_unwrap_unchecked", since = "1.58.0")]
     pub unsafe fn unwrap_unchecked(self) -> T {
+        debug_assert!(self.is_ok());
         match self {
             Ok(t) => t,
             // SAFETY: the safety contract must be upheld by the caller.
@@ -1512,6 +1513,7 @@ impl<T, E> Result<T, E> {
     #[track_caller]
     #[stable(feature = "option_result_unwrap_unchecked", since = "1.58.0")]
     pub unsafe fn unwrap_err_unchecked(self) -> E {
+        debug_assert!(self.is_err());
         match self {
             // SAFETY: the safety contract must be upheld by the caller.
             Ok(_) => unsafe { hint::unreachable_unchecked() },