If you're familiar with Data ONTAP's A-SIS (advanced single instance storage) deduplication technology that is integral to WAFL, then you're already there. SIS-clone (which may not be the official term) uses the same engine to clone files or LUNs rapidly by merely copying the block pointers.
The same mechanism can also clone block ranges, so Copy-NaHostFile in Toolkit 1.6 uses NTFS APIs to determine the block ranges for a file within a LUN mounted on the local host. It then clones only those ranges into a new file, so you get a near-instantaneous read/write clone without any data being copied on either the host or the storage controller or any additional space consumed within the Data ONTAP volume. It's a great way to clone VHD files, etc.
If you want to use the same mechanism to clone entire LUNs or files in CIFS shares, you can do that using the Toolkit cmdlets in the clone category:
PS C:\> Get-NaHelp -Category clone
Name Api Category
---- --- --------
Clear-NaClone {clone-clear} clone
Get-NaClone {clone-list-status} clone
Start-NaClone {clone-start} clone
Stop-NaClone {clone-stop} clone