Not infrequently, I discover I want to turn an if modifier into an if block so I can add extra logic when the conditional is true.
# from this do_something() if condition(); # to this if ( condition() ) { do_something(); }
I decided to automate that with a vim macro:
map ,if V:s/\(\s*\) if \(.*\);/\1if (\2) {/<CR>kVdp>>$a;<CR><BS>}<CR><Esc>kkk^
For it to work, the if modifier has to be on a line of its own (which I usually do for code clarity) and the cursor needs to be on that line when running the macro.
Feel free to copy and adapt to your own needs and preferences.