From e9cb8ec4b259f0aae1d406a9bdc5575c17046746 Mon Sep 17 00:00:00 2001
From: Nicolas Braud-Santoni <nicolas@braud-santoni.eu>
Date: Mon, 25 Nov 2019 23:12:07 +0700
Subject: [PATCH 1/2] construct::utils: Replace unecessary
 std::ptr::copy_nonoverlapping

When copying from different slices, std::slice::copy_from_slice is always
preferable: it implements bounds-checks, is safe, and also calls into memcpy.
---
 src/construct/utils.rs | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/src/construct/utils.rs b/src/construct/utils.rs
index ef5ff66..8e35be6 100644
--- a/src/construct/utils.rs
+++ b/src/construct/utils.rs
@@ -62,13 +62,7 @@ pub fn suffixes_from_substrs<'s, T, F>(
     // 2. sort lms suffixes
     if k + 1 == tail.len() {
         // lms substrings => lms suffixes
-        unsafe {
-            std::ptr::copy_nonoverlapping(
-                &tail[0] as *const u32,
-                &mut head[0] as *mut u32,
-                tail.len(),
-            );
-        }
+        &head[0..tail.len()].copy_from_slice(tail);
     } else {
         // construct sub-problem
         let mut t = 0;
@@ -83,13 +77,8 @@ pub fn suffixes_from_substrs<'s, T, F>(
         sort(&mut head[..t], k, tail);
 
         // rearrange the lms suffixes
-        unsafe {
-            std::ptr::copy_nonoverlapping(
-                &tail[0] as *const u32,
-                &mut head[0] as *mut u32,
-                tail.len(),
-            );
-        }
+        &head[0..tail.len()].copy_from_slice(tail);
+
         let mut h = tail.len();
         for_each_lms(s, true, |i, _| {
             h -= 1;

From 416cbb8e6548706501c24a823e04b86be1926e42 Mon Sep 17 00:00:00 2001
From: Nicolas Braud-Santoni <nicolas@braud-santoni.eu>
Date: Tue, 26 Nov 2019 11:04:07 +0700
Subject: [PATCH 2/2] construct::sacak::sacak_u32: Replace unnecessary
 std::ptr::copy

slice::copy_within supports safely copying within a given slice,
and is implemented with std::ptr::copy.
---
 src/construct/sacak/sacak_u32s/mod.rs | 29 +++++----------------------
 1 file changed, 5 insertions(+), 24 deletions(-)

diff --git a/src/construct/sacak/sacak_u32s/mod.rs b/src/construct/sacak/sacak_u32s/mod.rs
index a8478b0..68ac1df 100644
--- a/src/construct/sacak/sacak_u32s/mod.rs
+++ b/src/construct/sacak/sacak_u32s/mod.rs
@@ -122,13 +122,7 @@ fn sort_lms_suffixes(s: &[u32], sa: &mut [u32]) {
                 sa[q] = tmp;
             } else {
                 let t = q + 1 - m;
-                unsafe {
-                    std::ptr::copy(
-                        &sa[l] as *const u32,
-                        &mut sa[t] as *mut u32,
-                        m,
-                    );
-                }
+                sa.copy_within(l..l+m, t);
                 sa[l..Ord::min(r, t)].iter_mut().for_each(|i| *i = EMPTY);
             }
 
@@ -329,13 +323,7 @@ fn finish_head(sa: &mut [u32]) {
     for p in 1..sa.len() {
         if sa[p] > EMPTY {
             let n = -(sa[p] as i32) as usize;
-            unsafe {
-                std::ptr::copy(
-                    &sa[p + 1] as *const u32,
-                    &mut sa[p] as *mut u32,
-                    n,
-                );
-            }
+            sa.copy_within(p+1..p+n+1, p);
             sa[p + n] = EMPTY;
         }
     }
@@ -347,13 +335,7 @@ fn finish_tail(sa: &mut [u32]) {
     for p in (1..sa.len()).rev() {
         if sa[p] > EMPTY {
             let n = -(sa[p] as i32) as usize;
-            unsafe {
-                std::ptr::copy(
-                    &sa[p - n] as *const u32,
-                    &mut sa[p - n + 1] as *mut u32,
-                    n,
-                );
-            }
+            sa.copy_within(p-n..p, p-n+1);
             sa[p - n] = EMPTY;
         }
     }
@@ -367,9 +349,8 @@ fn sa_move(
     n: usize,
     ptr: &mut Option<&mut usize>,
 ) {
-    unsafe {
-        std::ptr::copy(&sa[src] as *const u32, &mut sa[dst] as *mut u32, n);
-    }
+    sa.copy_within(src..src+n, dst);
+
     if let Some(p) = std::mem::replace(ptr, None) {
         if *p >= src && *p < src + n {
             if dst >= src {