diff --git a/TODO b/TODO
index 5dcf131..d945cde 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,5 @@
 images
 text
 ui ctx = ui + app ctx for sensors
-free / delete widgets
 abstract sensors to work with any event, maybe associate data as well?
-make senses orable so you can select multiple
+make current senses orable so you can select multiple
diff --git a/src/core/span.rs b/src/core/span.rs
index 67f49d5..ac535dc 100644
--- a/src/core/span.rs
+++ b/src/core/span.rs
@@ -75,7 +75,7 @@ pub enum SpanLen {
     /// relative to remaining free space and other ratios
     /// eg. 1 and 2 would take up 1/3 and 2/3 of the remaining space (after others)
     Ratio(f32),
-    /// relative to the total space
+    /// relative to the total space (of the entire span)
     /// eg. 0.5 means 1/2 of the total space
     Relative(f32),
 }
diff --git a/src/layout/id.rs b/src/layout/id.rs
index 65a0cad..8f6dbcd 100644
--- a/src/layout/id.rs
+++ b/src/layout/id.rs
@@ -67,6 +67,7 @@ impl<W> WidgetId<W> {
     }
 
     pub(super) fn cast_type<W2>(self) -> WidgetId<W2> {
+        // safety: self is repr(C) and generic only used for phantom data
         unsafe { std::mem::transmute(self) }
     }