diff --git a/dub.sdl b/dub.sdl
index 78cdb3f..f52f6ad 100644
--- a/dub.sdl
+++ b/dub.sdl
@@ -26,7 +26,7 @@ buildType "release" {
 
 buildType "unittest" {
   buildOptions "unittests" "debugMode" "debugInfo"
-  dflags "-checkaction=context" "-preview=dip1000"
+  dflags "-checkaction=context" "-preview=dip1000" # TODO: "-preview=dip1021"
   dflags "-fsanitize=address" "-fsanitize=leak" platform="posix-ldc"
 }
 
diff --git a/perf.data b/perf.data
new file mode 100644
index 0000000..f4053bb
Binary files /dev/null and b/perf.data differ
diff --git a/perf.data.old b/perf.data.old
new file mode 100644
index 0000000..3ac7d83
Binary files /dev/null and b/perf.data.old differ