Is there an easy way to "capture" returns in Tcl?

I'd like to be able to insure that an action takes place upon exit from a Tcl proc. For example, I need to do something like this:

proc foo {} {
    variable var
    set saved $var
    # some stuff
    if {$failed} {
        set var $saved
        return
    }
    # more stuff
    set var $saved
}

Is there an easy way to do this, so I don't have to repeat the "exit" code at every return? Conceptually:

proc foo {} {
    variable var
    set saved $var
    set do-at-return {set var $saved}
    # some stuff
    if {$failed} {
        return
    }
    # more stuff
}

Where do-at-return would be executed whenever foo exits.

You can probably do complicated things with a "leave" execution trace, but an easier way is to wrap the relevant part of the body in a try/finally statement:

proc foo {} {
    variable var
    set saved $var
    try {
        # some stuff
        if {$failed} {
            return
        }
        # more stuff
    } finally {
        set var $saved
    }
}