Instead of using composeInput(), build a tuple type containing
the element types only, dropping ownership qualifiers and
asserting that there are no inout or vararg elements.
This is correct because we already promote +0 values to +1, or
clean up +1 values that are only used as +0 as needed.
Fixes <rdar://problem/44915136>.
Fix collection subtyping relation in function argument position
by emiting special re-abstraction thunk with collection upcast.
Resolves: rdar://problem/35702810
For Swift 3 / 4:
Deprecate the spelling "ImplicitlyUnwrappedOptional", emitting a warning
and suggesting "!" in places where they are allowed according to
SE-0054.
In places where SE-0054 disallowed IUOs but we continued to accept them
in previous compilers, emit a warning suggesting "Optional" or "?" as
an alternative depending on context and treat the IUO as an Optional,
noting this in the diagnostic.
For Swift 5:
Treat "ImplicitlyUnwrappedOptional" as an error, suggesting
"!" in places where they are allowed by SE-0054.
In places where SE-0054 disallowed IUOs, emit an error suggestion
"Optional" or "?" as an alternative depending on context.
This flips the switch to have @noescape be the default semantics for
function types in argument positions, for everything except property
setters. Property setters are naturally escaping, so they keep their
escaping-by-default behavior.
Adds contentual printing, and updates the test cases.
There is some further (non-source-breaking) work to be done for
SE-0103:
- We need the withoutActuallyEscaping function
- Improve diagnostics and QoI to at least @noescape's standards
- Deprecate / drop @noescape, right now we allow it
- Update internal code completion printing to be contextual
- Add more tests to explore tricky corner cases
- Small regressions in fixits in attr/attr_availability.swift
Also NSHipster is an actual website that exists, so let's use NSBurrito
as a placeholder name in the function_conversion_objc test instead.
Swift SVN r31550
