Take diff of two vertical opened windows in Vim

Question

I\'ve have two files opened. They are opened in vertical mode, next to next. Can I instantly diff these two files without leaving or closing Vim ?

Answer 1

Following on the earlier answers I adapted the mapping provided by @cxw. The following mapping automatically closes NERDTree and diffs the open windows. It does not matter if NERDTree is closed, it works the same way. I do this quite often so it saved me quite some time.

command! Difft NERDTreeClose | windo diffthis