This was discussed in:
- Design `?` to work on named blocks.
- https://github.com/rust-lang/rfcs/pull/2388#issuecomment-381352575
- https://github.com/rust-lang/rfcs/pull/2388#issuecomment-385136848
try (formerly catch) has been through 2 RFCs, unless new compelling arguments are presented I see no reason to go with 'label?.