Remove use of borrow_as from trace wrappers (#609)

Author: frankmcsherry

differential-dataflow/src/trace/wrappers/freeze.rs

@@ -26,7 +26,6 @@ use timely::progress::frontier::AntichainRef;
 use crate::operators::arrange::Arranged;
 use crate::trace::{TraceReader, BatchReader, Description};
 use crate::trace::cursor::Cursor;
-use crate::IntoOwned;
 
 /// Freezes updates to an arrangement using a supplied function.
 ///
@@ -78,7 +77,7 @@ where
     type Key<'a> = Tr::Key<'a>;
     type Val<'a> = Tr::Val<'a>;
     type Time = Tr::Time;
-    type TimeGat<'a> = Tr::TimeGat<'a>;
+    type TimeGat<'a> = &'a Tr::Time;
     type Diff = Tr::Diff;
     type DiffGat<'a> = Tr::DiffGat<'a>;
 
@@ -141,7 +140,7 @@ where
     type Key<'a> = B::Key<'a>;
     type Val<'a> = B::Val<'a>;
     type Time = B::Time;
-    type TimeGat<'a> = B::TimeGat<'a>;
+    type TimeGat<'a> = &'a B::Time;
     type Diff = B::Diff;
     type DiffGat<'a> = B::DiffGat<'a>;
 
@@ -185,7 +184,7 @@ where
     type Key<'a> = C::Key<'a>;
     type Val<'a> = C::Val<'a>;
     type Time = C::Time;
-    type TimeGat<'a> = C::TimeGat<'a>;
+    type TimeGat<'a> = &'a C::Time;
     type Diff = C::Diff;
     type DiffGat<'a> = C::DiffGat<'a>;
 
@@ -204,7 +203,7 @@ where
         let func = &self.func;
         self.cursor.map_times(storage, |time, diff| {
             if let Some(time) = func(time) {
-                logic(<Self::TimeGat<'_> as IntoOwned>::borrow_as(&time), diff);
+                logic(&time, diff);
             }
         })
     }
@@ -240,7 +239,7 @@ where
     type Key<'a> = C::Key<'a>;
     type Val<'a> = C::Val<'a>;
     type Time = C::Time;
-    type TimeGat<'a> = C::TimeGat<'a>;
+    type TimeGat<'a> = &'a C::Time;
     type Diff = C::Diff;
     type DiffGat<'a> = C::DiffGat<'a>;
 
@@ -259,7 +258,7 @@ where
         let func = &self.func;
         self.cursor.map_times(&storage.batch, |time, diff| {
             if let Some(time) = func(time) {
-                logic(<Self::TimeGat<'_> as IntoOwned>::borrow_as(&time), diff);
+                logic(&time, diff);
             }
         })
     }

differential-dataflow/src/trace/wrappers/frontier.rs

@@ -35,7 +35,7 @@ impl<Tr: TraceReader> TraceReader for TraceFrontier<Tr> {
     type Key<'a> = Tr::Key<'a>;
     type Val<'a> = Tr::Val<'a>;
     type Time = Tr::Time;
-    type TimeGat<'a> = Tr::TimeGat<'a>;
+    type TimeGat<'a> = &'a Tr::Time;
     type Diff = Tr::Diff;
     type DiffGat<'a> = Tr::DiffGat<'a>;
 
@@ -86,7 +86,7 @@ impl<B: BatchReader> BatchReader for BatchFrontier<B> {
     type Key<'a> = B::Key<'a>;
     type Val<'a> = B::Val<'a>;
     type Time = B::Time;
-    type TimeGat<'a> = B::TimeGat<'a>;
+    type TimeGat<'a> = &'a B::Time;
     type Diff = B::Diff;
     type DiffGat<'a> = B::DiffGat<'a>;
 
@@ -131,7 +131,7 @@ impl<C: Cursor> Cursor for CursorFrontier<C, C::Time> {
     type Key<'a> = C::Key<'a>;
     type Val<'a> = C::Val<'a>;
     type Time = C::Time;
-    type TimeGat<'a> = C::TimeGat<'a>;
+    type TimeGat<'a> = &'a C::Time;
     type Diff = C::Diff;
     type DiffGat<'a> = C::DiffGat<'a>;
 
@@ -156,7 +156,7 @@ impl<C: Cursor> Cursor for CursorFrontier<C, C::Time> {
             time.clone_onto(&mut temp);
             temp.advance_by(since);
             if !until.less_equal(&temp) {
-                logic(<Self::TimeGat<'_> as IntoOwned>::borrow_as(&temp), diff);
+                logic(&temp, diff);
             }
         })
     }
@@ -194,7 +194,7 @@ impl<C: Cursor<Storage: BatchReader>> Cursor for BatchCursorFrontier<C> {
     type Key<'a> = C::Key<'a>;
     type Val<'a> = C::Val<'a>;
     type Time = C::Time;
-    type TimeGat<'a> = C::TimeGat<'a>;
+    type TimeGat<'a> = &'a C::Time;
     type Diff = C::Diff;
     type DiffGat<'a> = C::DiffGat<'a>;
 
@@ -219,7 +219,7 @@ impl<C: Cursor<Storage: BatchReader>> Cursor for BatchCursorFrontier<C> {
             time.clone_onto(&mut temp);
             temp.advance_by(since);
             if !until.less_equal(&temp) {
-                logic(<Self::TimeGat<'_> as IntoOwned>::borrow_as(&temp), diff);
+                logic(&temp, diff);
             }
         })
     }