If a type conditionally conforms to BidirectionalCollection, suffix's (and the
others) use of `index` ends up dispatching through `Collection.index` seemingly
because it is a protocol requirement. The intended function is
BidirectionalCollection's overloaded `index` (which _isn't_ connected to a
protocol requirement), which is called for non-conditional conformances. As
such, this is a work-around to stop code crashing.
Noticed in SR-8022, rdar://problem/41216424.
- Revise Bool.toggle() discussion and fix attribute placement
- Revise to Hasher abstracts and discussions
- Correct the name of the remainder operator
- Clean up deprecations and paste-os w/in UnsafePointer
Improvements from SE-0213 made constant propagation more
precise but, as a side-effect, resulted in more false positives,
to mitigate that `magnitude` has marked as `@inline(__always)`
but it could be made transparent again by using `&+` operator.
Implementation is as follows: In `preCheckExpression` try to
detect if there is `T(literal)` call in the AST, replace it with
implicit `literal as T`, while trying to form type-checked AST,
after constraint solving, restore source information and drop
unnecessary coercion expression.
Resolves: rdar://problem/17088188
Resolves: rdar://problem/39120081
Resolves: rdar://problem/23672697
Resolves: rdar://problem/40379985
This allows Set’s internal types not to define Key, Value, SequenceElement & SequenceElementWithoutLabels typealiases.
Splitting the protocol on the mutable/immutable axis allows us to remove some obsolete method definitions.
LLVM specifies that the result of fptosi and fptoui instructions are
undefined if the target type cannot represent the value exactly. On
IBM Z (s390x) these instructions currently saturate when overflow
occurs. This means that the round-trip used to detect overflow
succeeds in situations where the conversion is not actually exact.
For example, casting Int32.max to a Float32 via a sitofp instruction
results in Int32.max + 1. This is inexact. However if we then convert
back to an Int32 via a fptosi instruction the result is clamped to
Int32.max and so the round trip has resulted in the same value. We
therefore cannot rely on round trips alone to verify the exactness
of this cast portably.
This commit modifies the conversion routines so that they do not
rely on undefined behavior and avoid using round trips in general.
Modifies SILGen and the `Swift._diagnoseUnexpectedNilOptional` call to print a slightly different message for force unwraps which were implicitly inserted by the compiler for IUOs. The message is chosen based on the presence of certain flags in the `ForceValueExpr`, not on the type of the value being unwrapped.
