Ability to preview changes as side-by-side diff before saving document

Coming from MediaWiki world this is the feature I miss the most so far - the ability to see changes to the latest version of the document as a side-by-side diff before saving the changes (an example of how it looks in MediaWiki is in the attachment).

Currently it is only possible to compare selected versions of the document on the document History page. Not sure if side-by-side view is available and if not then it would be great if such mode was also considered.

I personally find being able to verify the changes before saving a document essential. Rather than trying to remember where the modifications actually happened while editing, which can be tricky when the edit is large or multiple parts are modified in one go, you get a clear summary of changes. This also helps with preventing accidental changes and gives an opportunity to roll them back or correct before another revision of the document gets created. Prevention is better than cure.