The lambda (with default capture by reference) looks like a good (existing) option to me.

    On Friday, August 16, 2019, 6:51:44 PM CDT, Arthur O'Dwyer <arthur.j.odwyer_at_[hidden]> wrote:
 
 On Fri, Aug 16, 2019 at 7:43 PM Walt Karas via Std-Proposals <std-proposals_at_[hidden]> wrote:

 Another option would be to redefine 'break' as a void-returning expression, so that:
do { /* yada */ } while (0);
could become:
for ( ; ; break) { /* yada */ }
It's more readable if you know a loop isn't really a loop from the beginning.


Once you're making up new meanings for control-flow keywords, what would be wrong with
    { /* yada */ if (something) goto bottom; /* yada */ } bottom:;
or
    []() { /* yada */ if (something) return; /* yada */ }();
? C++ already has plenty of ways to spell "goto this place" and/or "break out of this level of nesting"; I don't think we need more.
"goto case" and "goto default", on the other hand, should probably Just Work. Try to get buy-in from a compiler vendor. I wouldn't want to waste paper verbiage on them before showing that they can be useful in practice.
my $.02,–Arthur