From 8644899714246fb4408a8c3e52004618590ea827 Mon Sep 17 00:00:00 2001
From: Vivianne Langdon <puttabutta@gmail.com>
Date: Tue, 26 Jul 2022 23:24:58 -0700
Subject: [PATCH] support getting ptrs or values, consistent between queue and
 table

---
 src/containers/queue.zig | 18 +++++++++++++++---
 src/containers/table.zig | 14 +++++++++++---
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/containers/queue.zig b/src/containers/queue.zig
index a3fcb90..4c5a95e 100644
--- a/src/containers/queue.zig
+++ b/src/containers/queue.zig
@@ -77,7 +77,9 @@ pub fn Queue(comptime T: type) type {
             self.backing[dst & mask] = val;
         }
 
-        pub fn popOrNull(self: *Self) ?T {
+        /// Pop pointer to the memory. This may be invalidated on any insert or remove,
+        /// so should be copied or discarded before that point.
+        pub fn popPtrOrNull(self: *Self) ?*T {
             if (self.size() <= 0) {
                 return null;
             }
@@ -88,11 +90,21 @@ pub fn Queue(comptime T: type) type {
             self.reads += 1;
 
             // (Same as % self.backing.len because power of 2)
-            return self.backing[src & mask];
+            return &self.backing[src & mask];
+        }
+
+        /// Pop pointer to the memory, but panic if null. This may be invalidated on any insert or remove,
+        /// so should be copied or discarded before that point.
+        pub fn popPtr(self: *Self) *T {
+            return self.popPtrOrNull() orelse unreachable;
+        }
+
+        pub fn popOrNull(self: *Self) ?T {
+            return if (self.popPtrOrNull()) |ptr| ptr.* else null;
         }
 
         pub fn pop(self: *Self) T {
-            return self.popOrNull() orelse unreachable;
+            return self.popPtr().*;
         }
     };
 }
diff --git a/src/containers/table.zig b/src/containers/table.zig
index e48989c..ce46b8f 100644
--- a/src/containers/table.zig
+++ b/src/containers/table.zig
@@ -156,10 +156,14 @@ pub fn Table(comptime K: type, comptime V: type) type {
             return val;
         }
 
-        pub fn get(self: *Self, id: Id) ?*V {
+        pub fn getPtr(self: *Self, id: Id) ?*V {
             return if (self.exists(id)) &(self.values.items[id.index] orelse unreachable) else null;
         }
 
+        pub fn get(self: *Self, id: Id) ?V {
+            return if (self.getPtr(id)) |ptr| ptr.* else null;
+        }
+
         pub fn find(self: *Self, key: K) ?Id {
             if (self.lookup.get(key)) |index| {
                 const gen = self.gens.items[index];
@@ -265,7 +269,7 @@ test "table across generation" {
     try std.testing.expectEqual(@as(u8, 1), second_result.id.gen);
 
     try std.testing.expect(!table.exists(first_result.id));
-    try std.testing.expectEqual(@as(?*TestVal, null), table.get(first_result.id));
+    try std.testing.expectEqual(@as(?*TestVal, null), table.getPtr(first_result.id));
 }
 
 test "table iteration" {
@@ -402,7 +406,11 @@ pub fn RefTable(comptime K: type, comptime V: type) type {
             return result;
         }
 
-        pub fn get(self: *Self, id: Id) ?*V {
+        pub fn getPtr(self: *Self, id: Id) ?*V {
+            return self.table.getPtr(id);
+        }
+
+        pub fn get(self: *Self, id: Id) ?V {
             return self.table.get(id);
         }