From 087017f9e8ba84d92a76bec17b2376f72c8e3a27 Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Thu, 7 May 2026 18:58:20 +0300
Subject: [PATCH] a basic owning reference implementation

---
 .gitignore   |  1 +
 Cargo.lock   |  7 ++++++
 Cargo.toml   |  6 +++++
 rustfmt.toml |  1 +
 src/lib.rs   | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 78 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 rustfmt.toml
 create mode 100644 src/lib.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..c16424d
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "ownref"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..b84c1a2
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "ownref"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/rustfmt.toml b/rustfmt.toml
new file mode 100644
index 0000000..218e203
--- /dev/null
+++ b/rustfmt.toml
@@ -0,0 +1 @@
+hard_tabs = true
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..fff84a5
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,63 @@
+use std::{
+	marker::PhantomData,
+	mem::ManuallyDrop,
+	ops::{Deref, DerefMut},
+	ptr::{self, NonNull},
+};
+
+pub struct OwnRef<'a, T: ?Sized>(Option<NonNull<T>>, PhantomData<&'a mut T>);
+
+impl<T: ?Sized> Drop for OwnRef<'_, T> {
+	fn drop(&mut self) {
+		let Some(p) = self.0 else { return };
+		unsafe { ptr::drop_in_place(p.as_ptr()) };
+	}
+}
+
+impl<T: ?Sized> Deref for OwnRef<'_, T> {
+	type Target = T;
+	fn deref(&self) -> &Self::Target {
+		unsafe { self.0.unwrap().as_ref() }
+	}
+}
+
+impl<T: ?Sized> DerefMut for OwnRef<'_, T> {
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		unsafe { self.0.unwrap().as_mut() }
+	}
+}
+
+impl<T: ?Sized> OwnRef<'_, T> {
+	pub unsafe fn new_unchecked(p: *mut T) -> Self {
+		Self(Some(NonNull::new(p).unwrap()), PhantomData)
+	}
+}
+
+impl<'a, T: ?Sized> OwnRef<'a, T> {
+	pub unsafe fn from_manually_drop(p: &'a mut ManuallyDrop<T>) -> Self {
+		unsafe { Self::new_unchecked(p.deref_mut() as *mut _) }
+	}
+}
+
+impl<T: Sized> OwnRef<'_, T> {
+	pub fn take(mut self) -> T {
+		let p = self.0.take().unwrap();
+		unsafe { p.read() }
+	}
+}
+
+impl OwnRef<'_, dyn std::any::Any> {
+	pub fn take<U: 'static>(mut self) -> Option<U> {
+		if !self.is::<U>() {
+			return None;
+		}
+		let p = self.0.take().unwrap();
+		let p = p.cast::<U>();
+		Some(unsafe { p.read() })
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+}