1 files changed, 37 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/as_ptr_cast_mut.rs b/src/tools/clippy/tests/ui/as_ptr_cast_mut.rs
new file mode 100644
index 000000000..0d1d92584
--- /dev/null
+++ b/src/tools/clippy/tests/ui/as_ptr_cast_mut.rs
@@ -0,0 +1,37 @@
+#![allow(unused)]
+#![warn(clippy::as_ptr_cast_mut)]
+#![allow(clippy::wrong_self_convention)]
+
+struct MutPtrWrapper(Vec<u8>);
+impl MutPtrWrapper {
+    fn as_ptr(&mut self) -> *const u8 {
+        self.0.as_mut_ptr() as *const u8
+    }
+}
+
+struct Covariant<T>(*const T);
+impl<T> Covariant<T> {
+    fn as_ptr(self) -> *const T {
+        self.0
+    }
+}
+
+fn main() {
+    let mut string = String::new();
+    let _ = string.as_ptr() as *mut u8;
+    let _: *mut i8 = string.as_ptr() as *mut _;
+    let _ = string.as_ptr() as *const i8;
+    let _ = string.as_mut_ptr();
+    let _ = string.as_mut_ptr() as *mut u8;
+    let _ = string.as_mut_ptr() as *const u8;
+
+    let nn = std::ptr::NonNull::new(4 as *mut u8).unwrap();
+    let _ = nn.as_ptr() as *mut u8;
+
+    let mut wrap = MutPtrWrapper(Vec::new());
+    let _ = wrap.as_ptr() as *mut u8;
+
+    let mut local = 4;
+    let ref_with_write_perm = Covariant(std::ptr::addr_of_mut!(local) as *const _);
+    let _ = ref_with_write_perm.as_ptr() as *mut u8;
+}