From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:02:58 +0200
Subject: Adding upstream version 1.64.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../const-generics/type-dependent/issue-61936.rs   | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 src/test/ui/const-generics/type-dependent/issue-61936.rs

(limited to 'src/test/ui/const-generics/type-dependent/issue-61936.rs')

diff --git a/src/test/ui/const-generics/type-dependent/issue-61936.rs b/src/test/ui/const-generics/type-dependent/issue-61936.rs
new file mode 100644
index 000000000..7216b25f0
--- /dev/null
+++ b/src/test/ui/const-generics/type-dependent/issue-61936.rs
@@ -0,0 +1,47 @@
+// run-pass
+
+trait SliceExt<T: Clone> {
+    fn array_windows_example<'a, const N: usize>(&'a self) -> ArrayWindowsExample<'a, T, N>;
+}
+
+impl <T: Clone> SliceExt<T> for [T] {
+   fn array_windows_example<'a, const N: usize>(&'a self) -> ArrayWindowsExample<'a, T, N> {
+       ArrayWindowsExample{ idx: 0, slice: &self }
+   }
+}
+
+struct ArrayWindowsExample<'a, T, const N: usize> {
+    slice: &'a [T],
+    idx: usize,
+}
+
+impl <'a, T: Clone, const N: usize> Iterator for ArrayWindowsExample<'a, T, N> {
+    type Item = [T; N];
+    fn next(&mut self) -> Option<Self::Item> {
+        // Note: this is unsound for some `T` and not meant as an example
+        // on how to implement `ArrayWindows`.
+        let mut res = unsafe{ std::mem::zeroed() };
+        let mut ptr = &mut res as *mut [T; N] as *mut T;
+
+        for i in 0..N {
+            match self.slice[self.idx..].get(i) {
+                None => return None,
+                Some(elem) => unsafe { std::ptr::write_volatile(ptr, elem.clone())},
+            };
+            ptr = ptr.wrapping_add(1);
+            self.idx += 1;
+        }
+
+        Some(res)
+    }
+}
+
+const FOUR: usize = 4;
+
+fn main() {
+    let v: Vec<usize> = vec![0; 100];
+
+    for array in v.as_slice().array_windows_example::<FOUR>() {
+        assert_eq!(array, [0, 0, 0, 0])
+    }
+}
-- 
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