feat(ecs): add relationships

1 files changed, 16 insertions, 0 deletions

diff --git a/ecs/src/lock.rs b/ecs/src/lock.rs
index c8a8495..b3c9f57 100644
--- a/ecs/src/lock.rs
+++ b/ecs/src/lock.rs
@@ -1,3 +1,4 @@
+use std::mem::transmute;
 use std::ops::{Deref, DerefMut};
 use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard, TryLockError};
 
@@ -73,6 +74,21 @@ where
     inner: RwLockReadGuard<'guard, Value>,
 }
 
+impl<'guard, Value> ReadGuard<'guard, Value>
+where
+    Value: TypeName,
+{
+    /// Converts the `ReadGuard` to a `ReadGuard` with a possibly longer lifetime.
+    ///
+    /// # Safety
+    /// The returned `ReadGuard` must **NOT** be used for longer than the original
+    /// lifetime.
+    pub unsafe fn upgrade_lifetime<'new>(self) -> ReadGuard<'new, Value>
+    {
+        unsafe { transmute(self) }
+    }
+}
+
 impl<'guard, Value> Deref for ReadGuard<'guard, Value>
 where
     Value: TypeName,