Reverts apple/swift#30006. It caused a regression that we'd like to address before re-landing:
```swift
struct X {
var cgf: CGFloat
}
func test(x: X?) {
let _ = (x?.cgf ?? 0) <= 0.5
}
```
This reverts commit 0a6b444b49.
This reverts commit ed255596a6.
This reverts commit 3e01160a2f.
This reverts commit 96297b7e39.
Resolves: rdar://problem/60185506
Enable solver to transitively infer bindings through argument conversion
constraints. That helps to infer bindings for (generic) parameters
from their arguments e.g.
```swift
func foo<T: ExpressibleByStringLiteral>(_: String, _: T) -> T {
fatalError()
}
func bar(_: Any?) {}
func test() {
bar(foo("", ""))
}
```
In this case `T` can currently only be inferred as `Any?`
(based on parameter type of `bar`) although a complete
set of bindings for that type variable includes `String`
as well, which comes from use of `T` in argument position.
Resolves: rdar://problem/56212087
We were using a precondition which crashes the program when invalid input is
provided. We want to provide a way to gracefully check and handle invalid input
or shutdown the program if necessary.
SR-1930
change includes both the necessary protocol updates and the deprecation
warnings
suitable for migration. A future patch will remove the renamings and
make this
a hard error.
The rule changes are as follows:
* All functions (introduced with the 'func' keyword) have argument
labels for arguments beyond the first, by default. Methods are no
longer special in this regard.
* The presence of a default argument no longer implies an argument
label.
The actual changes to the parser and printer are fairly simple; the
rest of the noise is updating the standard library, overlays, tests,
etc.
With the standard library, this change is intended to be API neutral:
I've added/removed #'s and _'s as appropriate to keep the user
interface the same. If we want to separately consider using argument
labels for more free functions now that the defaults in the language
have shifted, we can tackle that separately.
Fixes rdar://problem/17218256.
Swift SVN r27704
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
When the solver has attempted to produce a solution using the default
literal type tha has failed, dont' try every type that conforms to
that literal type. Instead, try the bridged class type (which deals
with the common AnyObject case) or one of two other options:
- For integer literals, try the default floating point type (Double)
- For string literals, try the standard library's AssertString (this
is a temporary hack)
This limits exponential blow-up in cases where the literal's type
cannot be determined from context. Addresses rdar://problem/18307267.
Swift SVN r22131
