优化代码结构

slice.go

@@ -0,0 +1,15 @@
+package docxlib
+
+import "unsafe"
+
+// slice is the runtime representation of a slice.
+// It cannot be used safely or portably and its representation may
+// change in a later release.
+//
+// Unlike reflect.SliceHeader, its Data field is sufficient to guarantee the
+// data it references will not be garbage collected.
+type slice struct {
+	data unsafe.Pointer
+	len  int
+	cap  int
+}