* [SR-4005] Allow heterogenous comparisons in elementsEqual
When a user is supplying a predicate to compare the type equivalence
isn’t required
* elementsEqualWithPredicate tests
Compares a string of a number with an integer value by using the
elementsEqualPredicate closure
* Update test expectations to use new sequence element types
* Update hardcoded test to reference sequence
- Revisions to unsafeDowncast and withVaList
- Fix the Int64/UInt64 discussion
- Buffer pointer revisions
- Fix Optional example to use new integer methods
- Revise and correct some UnsafeRawBufferPointer docs
- Fix symmetricDifference examples
- Fix wording in FloatingPoint.nextDown
- Update ImplicitlyUnwrappedOptional
- Clarify elementsEqual
- Minor integer doc fixes
- Comment for _AppendKeyPath
- Clarification re collection indices
- Revise RangeExpression.relative(to:)
- Codable revisions
Implement and document `reduce(into:_:)`, with a few notes:
- The `initial` parameter was renamed `initialResult` to match the first parameter in `reduce(_:_:)`.
- The unnamed `combining` parameter was renamed `updateAccumulatingResult` to try and resemble the naming of the closure parameter in `reduce(_:_:)`.
- The closure throws and `reduce(into:_)` re-throws.
- This documentation mentions that `reduce(into:_)` is preferred over `reduce(_:_:)` when the result is a copy-on-write type and an example where the result is a dictionary.
Add benchmarks for reduce with accumulation into a scalar, an array, and a dictionary.
Update expected error message in closures test (since there are now two `reduce` methods, the diagnostic is different).
* Give Sequence a top-level Element, constrain Iterator to match
* Remove many instances of Iterator.
* Fixed various hard-coded tests
* XFAIL a few tests that need further investigation
* Change assoc type for arrayLiteralConvertible
* Mop up remaining "better expressed as a where clause" warnings
* Fix UnicodeDecoders prototype test
* Fix UIntBuffer
* Fix hard-coded Element identifier in CSDiag
* Fix up more tests
* Account for flatMap changes
* removing .characters from examples
* beginning new String doc revisions
* improvements to the String Foundation overlay docs
* minor revisions elsewhere
* [stdlib] Backward compatibility fix for a flatMap on [String]
Since String started to conform to Collection, the flatMap with a
sequence returning closure is now a better match that the one that
relies on the optional promotion in this code:
[""].flatMap { $0 }
which results in the default type of this expression changing from
[String] to [Character].
Restoring the old behavior in Swift 3 mode by adding a very explicit
overload.
Fixes: <rdar://problem/32024978>
* [stdlib] Fixing another compatibility issue with [String].flatMap
The following code behaves incorrectly due to the presence of this
overload.
let a: Int = 1
let b: Int? = 2
let c: Int? = nil
let result: [Any] = [a, b, c].flatMap { $0 }
Fixes: <rdar://problem/31910642>
Due to implicit promotion to optional it is possible to call flatMap
with a closure, that does not return an optional. This way the code
works, but is unnecessary inefficient. Such uses of flatMap can and
should be replaced with map.
In max() method’s documentation comment, The explanation says “This
example finds the smallest value in an array of height measurements.”
But, it should be “the largest value”. This commit fixes this
documentation error.
