Add the tests for manual_memcpy with loop counters

Author: rail-rain

tests/ui/manual_memcpy.rs

@@ -115,6 +115,60 @@ pub fn manual_copy(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) {
     }
 }
 
+#[allow(clippy::needless_range_loop, clippy::explicit_counter_loop)]
+pub fn manual_copy_with_counters(src: &[i32], dst: &mut [i32], dst2: &mut [i32]) {
+    let mut count = 0;
+    for i in 3..src.len() {
+        dst[i] = src[count];
+        count += 1;
+    }
+
+    let mut count = 0;
+    for i in 3..src.len() {
+        dst[count] = src[i];
+        count += 1;
+    }
+
+    let mut count = 3;
+    for i in 0..src.len() {
+        dst[count] = src[i];
+        count += 1;
+    }
+
+    let mut count = 3;
+    for i in 0..src.len() {
+        dst[i] = src[count];
+        count += 1;
+    }
+
+    let mut count = 0;
+    for i in 3..(3 + src.len()) {
+        dst[i] = src[count];
+        count += 1;
+    }
+
+    let mut count = 3;
+    for i in 5..src.len() {
+        dst[i] = src[count - 2];
+        count += 1;
+    }
+
+    let mut count = 5;
+    for i in 3..10 {
+        dst[i] = src[count];
+        count += 1;
+    }
+
+    let mut count = 3;
+    let mut count = 30;
+    for i in 0..src.len() {
+        dst[count] = src[i];
+        dst2[count] = src[i];
+        count += 1;
+        count += 1;
+    }
+}
+
 #[warn(clippy::needless_range_loop, clippy::manual_memcpy)]
 pub fn manual_clone(src: &[String], dst: &mut [String]) {
     for i in 0..src.len() {

tests/ui/manual_memcpy.stderr

@@ -16,7 +16,7 @@ error: it looks like you're manually copying between slices
   --> $DIR/manual_memcpy.rs:17:14
    |
 LL |     for i in 0..src.len() {
-   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[10..])`
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[10..(src.len() + 10)])`
 
 error: it looks like you're manually copying between slices
   --> $DIR/manual_memcpy.rs:22:14
@@ -79,10 +79,64 @@ LL |     for i in 0..0 {
    |              ^^^^ help: try replacing the loop by: `dst[..0].clone_from_slice(&src[..0])`
 
 error: it looks like you're manually copying between slices
-  --> $DIR/manual_memcpy.rs:120:14
+  --> $DIR/manual_memcpy.rs:121:14
+   |
+LL |     for i in 3..src.len() {
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[3..src.len()].clone_from_slice(&src[..(src.len() - 3)])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:127:14
+   |
+LL |     for i in 3..src.len() {
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[..(src.len() - 3)].clone_from_slice(&src[3..])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:133:14
+   |
+LL |     for i in 0..src.len() {
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[3..(src.len() + 3)].clone_from_slice(&src[..])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:139:14
+   |
+LL |     for i in 0..src.len() {
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[3..(src.len() + 3)])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:145:14
+   |
+LL |     for i in 3..(3 + src.len()) {
+   |              ^^^^^^^^^^^^^^^^^^ help: try replacing the loop by: `dst[3..(3 + src.len())].clone_from_slice(&src[..((3 + src.len()) - 3)])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:151:14
+   |
+LL |     for i in 5..src.len() {
+   |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[5..src.len()].clone_from_slice(&src[(3 - 2)..((src.len() - 2) + 3 - 5)])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:157:14
+   |
+LL |     for i in 3..10 {
+   |              ^^^^^ help: try replacing the loop by: `dst[3..10].clone_from_slice(&src[5..(10 + 5 - 3)])`
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:164:14
+   |
+LL |     for i in 0..src.len() {
+   |              ^^^^^^^^^^^^
+   |
+help: try replacing the loop by
+   |
+LL |     for i in dst[3..(src.len() + 3)].clone_from_slice(&src[..])
+LL |     dst2[30..(src.len() + 30)].clone_from_slice(&src[..]) {
+   |
+
+error: it looks like you're manually copying between slices
+  --> $DIR/manual_memcpy.rs:174:14
    |
 LL |     for i in 0..src.len() {
    |              ^^^^^^^^^^^^ help: try replacing the loop by: `dst[..src.len()].clone_from_slice(&src[..])`
 
-error: aborting due to 13 previous errors
+error: aborting due to 21 previous errors