Refactor deinitIfLive: adjust return type and parameter naming; update allocator usage in main.zig

src/memory/util.zig

@@ -1,27 +1,27 @@
 const std = @import("std");
 
-/// Deinitializes `allocator` only if it is still live.
+/// Deinitializes `resource` only if it is still live.
 ///
-/// Pass a pointer to the original allocator owner, such as an
-/// `ArenaAllocator` or `DebugAllocator`.
+/// Pass a pointer to the original allocator owner,
+/// such as an `ArenaAllocator`.
 ///
 /// If `live` is `true`, calls `allocator.deinit()` and then sets
 /// `live` to `false`, preventing a later cleanup path from attempting
 /// to deinitialize the same allocator again.
 ///
-/// The return value of `deinit()` is discarded.
-pub fn deinitIfLive(allocator: anytype, live: *bool) void
+/// The return value of `deinit()` is returned from the function.
+pub fn deinitIfLive(resource: anytype, live: *bool) ?@TypeOf(resource.deinit())
 {
     comptime
     {
-        const T = @TypeOf(allocator);
+        const T = @TypeOf(resource);
 
         if (@typeInfo(T) != .pointer) @compileError("deinitIfLive expects a pointer!");
         if (T == std.mem.Allocator)   @compileError("deinitIfLive expects a pointer to an allocator owner, not std.mem.Allocator!");
     }
 
-    if (live.*) {
-        _ = allocator.deinit();
-        live.* = false;
-    }
+    if (!live.*) return null;
+
+    live.* = false;
+    return resource.deinit();
 }