use is_multiple_of instead of manual modulo

Author: folkertdev

core/src/slice/mod.rs

@@ -1316,7 +1316,7 @@ impl<T> [T] {
         assert_unsafe_precondition!(
             check_language_ub,
             "slice::as_chunks_unchecked requires `N != 0` and the slice to split exactly into `N`-element chunks",
-            (n: usize = N, len: usize = self.len()) => n != 0 && len % n == 0,
+            (n: usize = N, len: usize = self.len()) => n != 0 && len.is_multiple_of(n),
         );
         // SAFETY: Caller must guarantee that `N` is nonzero and exactly divides the slice length
         let new_len = unsafe { exact_div(self.len(), N) };
@@ -1512,7 +1512,7 @@ impl<T> [T] {
         assert_unsafe_precondition!(
             check_language_ub,
             "slice::as_chunks_unchecked requires `N != 0` and the slice to split exactly into `N`-element chunks",
-            (n: usize = N, len: usize = self.len()) => n != 0 && len % n == 0
+            (n: usize = N, len: usize = self.len()) => n != 0 && len.is_multiple_of(n)
         );
         // SAFETY: Caller must guarantee that `N` is nonzero and exactly divides the slice length
         let new_len = unsafe { exact_div(self.len(), N) };
@@ -4866,7 +4866,7 @@ impl<T> [T] {
 
         let byte_offset = elem_start.wrapping_sub(self_start);
 
-        if byte_offset % size_of::<T>() != 0 {
+        if !byte_offset.is_multiple_of(size_of::<T>()) {
             return None;
         }
 
@@ -4920,7 +4920,7 @@ impl<T> [T] {
 
         let byte_start = subslice_start.wrapping_sub(self_start);
 
-        if byte_start % size_of::<T>() != 0 {
+        if !byte_start.is_multiple_of(size_of::<T>()) {
             return None;
         }
 

core/src/slice/sort/shared/smallsort.rs

@@ -823,7 +823,7 @@ unsafe fn bidirectional_merge<T: FreezeMarker, F: FnMut(&T, &T) -> bool>(
         let right_end = right_rev.wrapping_add(1);
 
         // Odd length, so one element is left unconsumed in the input.
-        if len % 2 != 0 {
+        if !len.is_multiple_of(2) {
             let left_nonempty = left < left_end;
             let last_src = if left_nonempty { left } else { right };
             ptr::copy_nonoverlapping(last_src, dst, 1);

core/src/str/count.rs

@@ -52,7 +52,7 @@ fn do_count_chars(s: &str) -> usize {
     // Check the properties of `CHUNK_SIZE` and `UNROLL_INNER` that are required
     // for correctness.
     const _: () = assert!(CHUNK_SIZE < 256);
-    const _: () = assert!(CHUNK_SIZE % UNROLL_INNER == 0);
+    const _: () = assert!(CHUNK_SIZE.is_multiple_of(UNROLL_INNER));
 
     // SAFETY: transmuting `[u8]` to `[usize]` is safe except for size
     // differences which are handled by `align_to`.

core/src/str/validations.rs

@@ -219,7 +219,7 @@ pub(super) const fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
             // Ascii case, try to skip forward quickly.
             // When the pointer is aligned, read 2 words of data per iteration
             // until we find a word containing a non-ascii byte.
-            if align != usize::MAX && align.wrapping_sub(index) % USIZE_BYTES == 0 {
+            if align != usize::MAX && align.wrapping_sub(index).is_multiple_of(USIZE_BYTES) {
                 let ptr = v.as_ptr();
                 while index < blocks_end {
                     // SAFETY: since `align - index` and `ascii_block_size` are