Squashed 'backend/goldmark/' content from commit 379bf24

git-subtree-dir: backend/goldmark
git-subtree-split: 379bf24a47e6ef07f34d7536aead86d8792ac300

util/util_unsafe_go121.go

@@ -0,0 +1,18 @@
+//go:build !appengine && !js && go1.21
+// +build !appengine,!js,go1.21
+
+package util
+
+import (
+	"unsafe"
+)
+
+// BytesToReadOnlyString returns a string converted from given bytes.
+func BytesToReadOnlyString(b []byte) string {
+	return unsafe.String(unsafe.SliceData(b), len(b))
+}
+
+// StringToReadOnlyBytes returns bytes converted from given string.
+func StringToReadOnlyBytes(s string) []byte {
+	return unsafe.Slice(unsafe.StringData(s), len(s))
+}