trust + fix redraw bug

core/src/util/mod.rs

@@ -1,4 +1,3 @@
-mod typemap;
 mod arena;
 mod borrow;
 mod change;
@@ -6,9 +5,10 @@ mod id;
 mod math;
 mod refcount;
 mod slot;
+mod trust;
+mod typemap;
 mod vec2;
 
-pub use typemap::*;
 pub use arena::*;
 pub use borrow::*;
 pub use change::*;
@@ -16,6 +16,8 @@ pub use id::*;
 pub use math::*;
 pub use refcount::*;
 pub use slot::*;
+pub use trust::*;
+pub use typemap::*;
 pub use vec2::*;
 
 pub type HashMap<K, V> = fxhash::FxHashMap<K, V>;

core/src/util/trust.rs

@@ -0,0 +1,17 @@
+#[allow(clippy::missing_safety_doc)]
+pub unsafe fn forget_ref<'a, T>(x: &T) -> &'a T {
+    unsafe { std::mem::transmute::<&T, &T>(x) }
+}
+
+#[allow(clippy::missing_safety_doc)]
+pub unsafe fn forget_mut<'a, T>(x: &mut T) -> &'a mut T {
+    unsafe { std::mem::transmute::<&mut T, &mut T>(x) }
+}
+
+#[allow(clippy::mut_from_ref, clippy::missing_safety_doc)]
+pub unsafe fn to_mut<T>(x: &T) -> &mut T {
+    #[allow(mutable_transmutes)]
+    unsafe {
+        std::mem::transmute::<&T, &mut T>(x)
+    }
+}