Use unchecked construction in Layout::pad_to_align.

nnethercote · nnethercote · commit 9b86a7177aeb · 2021-11-26T19:30:35.000+11:00
Other, similar methods for `Layout` do likewise, and there's already an
`unwrap()` around the result demonstrating the safety.
diff --git a/core/src/alloc/layout.rs b/core/src/alloc/layout.rs
@@ -281,7 +281,9 @@ impl Layout {
         // > `usize::MAX`)
         let new_size = self.size() + pad;
 
-        Layout::from_size_align(new_size, self.align()).unwrap()
+        // SAFETY: self.align is already known to be valid and new_size has been
+        // padded already.
+        unsafe { Layout::from_size_align_unchecked(new_size, self.align()) }
     }
 
     /// Creates a layout describing the record for `n` instances of

Original file line number	Diff line number	Diff line change
`@@ -281,7 +281,9 @@ impl Layout {`
`281`	`281`	// > `usize::MAX`)
`282`	`282`	`let new_size = self.size() + pad;`
`283`	`283`
`284`		`- Layout::from_size_align(new_size, self.align()).unwrap()`
	`284`	`+ // SAFETY: self.align is already known to be valid and new_size has been`
	`285`	`+ // padded already.`
	`286`	`+ unsafe { Layout::from_size_align_unchecked(new_size, self.align()) }`
`285`	`287`	`}`
`286`	`288`
`287`	`289`	/// Creates a layout describing the record for `n` instances of