+/**
+ * EXPERIMENTAL, since wimlib v1.9.0: create a temporary filesystem snapshot of
+ * the source directory and add the files from it. Currently, this option is
+ * only supported on Windows, where it uses the Volume Shadow Copy Service
+ * (VSS). Using this option, you can create a consistent backup of the system
+ * volume of a running Windows system without running into problems with locked
+ * files. For the VSS snapshot to be successfully created, your application
+ * must be run as an Administrator, and it cannot be run in WoW64 mode (i.e. if
+ * Windows is 64-bit, then your application must be 64-bit as well).
+ */
+#define WIMLIB_ADD_FLAG_SNAPSHOT 0x00008000
+