ios - How do I call animateAlongsideTransition in Swift? -

i've tried many combinations in order call animatealongsidetransition in swift transition coordinator. feel i'm missing stupid.

if want call (from swift docs):

func animatealongsidetransition(_ animation: ((uiviewcontrollertransitioncoordinatorcontext!) -> void)!,                      completion completion: ((uiviewcontrollertransitioncoordinatorcontext!) -> void)!) -> bool 

how it? want pass things in animation block , nothing in completion block.

this want do:

coordinator.animatealongsidetransition({ context in         // whatever context         context.viewcontrollerforkey(uitransitioncontextfromviewcontrollerkey)     }, completion: nil) 

you can omit parameters if use variables $0 first implicit parameter , so

coordinator.animatealongsidetransition({         $0.viewcontrollerforkey(uitransitioncontextfromviewcontrollerkey)     }, completion: nil) 

the in syntax surprises @ first, have learn once :)

• the curly brackets defines block inside function
• you use in separate parameters block body
• but said above, can omit parameters using $0, $1, $2 , so...

it seems there's more verbose syntax, not fits swift spirit (and i'm lazy post there)

hope helps (and don't forget anything...)

edit:

another pro tip when block parameter, can omit parentheses
(the next not work, it's figure idea)

coordinator.animatealongsidetransition{         $0.viewcontrollerforkey(uitransitioncontextfromviewcontrollerkey)     }