Hello, Swift community!
The review of SE-0521: Improved Syntax for Optionals of Opaque and Existential Types ran from March 16th through March 30th, 2026. The Language Steering Group has decided to accept the proposal with the additional modification that the ergonomic syntax treatment be extended to suppressed constraints as well. That is, it will additionally be possible to write, e.g., any ~Copyable? and have this mean the same thing as (any ~Copyable)? (the same also applies to some). Because the 'bare' ~Copyable syntax in type position (without any or some) already produces a warning, we will not extend such special treatment to this case.
Discussion in the review thread was limited but quite positive overall. Aside from the modification discussed above, the only other point discussed was whether we should use the new syntax in .swiftinterface files when possible. The LSG agreed that it was desirable to continue printing the parentheses-disambiguated form in these files since they are not primarily intended for human consumption.
Thank you to everyone who participated in the review!
Freddy Kellison-Linn
Review Manager