Allow Inverse selection
Use cases
Sometimes there are a lot of .zip files in a folder.
You select them all, right click, and then "Extract here".
When the extraction finishes, nautilus automatically select all the extracted folders.
But then you don't need the zip files anymore.
It would be useful a right-click context option "invert selection", to select the zip files again and then press "canc" to delete them all.
This is just an example of an use case of the feature.
Desired behavior
Right-click->Invert selection
Will select all the files and folders ina a given folder that are not currently select, and de-select the currently selected ones
Benefits of the solution
Easier to manage files
Possible drawbacks
The user may inadvertently select files it doesn't want to really delete
Edited by Andre Klapper