Always add constraints, find fixes during simplify.
New separate fix for allow generic function specialization.
Improve parse heuristic for isGenericTypeDisambiguatingToken.
Degrade concrete type specialization fix to warning for macros.
Doing it in the post-walk meant we ended up
walking the children twice, which lead to duplicate
diagnostics and incorrect inference of the
level of application for function references. Move
it to the pre-walk, ensuring that we resolve any
operator references before folding.
Always add constraints, find fixes during simplify.
New separate fix for allow generic function specialization.
Improve parse heuristic for isGenericTypeDisambiguatingToken.
Previously we could end up with a
ContextualMismatch fix and a MissingConformance fix
for different elements of the `matchTypes` disjunction,
leading to an ambiguity. Instead, avoid recording
the ContextualMismatch if we're matching an
existential, and tweak the MissingConformance
failure to have a custom diagnostic for
EnumElementPattern matching.
Make sure `CouldNotInferPlaceholderType` can
produce a diagnostic for a `PlaceholderType`
locator element, and avoid emitting an extra
diagnostic for a placeholder type in an invalid
position.
If closure appears inside of a pack expansion, the elements
that reference pack elements have to bring expansion's shape
type in scope to make sure that the shapes match.
Type variable reference collector needs to be augmented to collect
type variables associated with pack expansions that a closure references
elements of, otherwise it would get disconnected from the context.
Stored `let` properties of a struct, class, or actor permit
'inout' modification within the constructor body after they have been
initialized. Tentatively remove this rule, only allowing such `let`
properties to be initialized (assigned to) and not treated as `inout`.
Fixes rdar://127258363.
Inference cannot be allowed in cases where both sides are type
variables and optional type is l-value capable because it results
in binding "optional" to an optional type and later discovering
a contextual type that is l-value optional i.e. if "optional type"
is resolved by selecting subscript overload.
* Revert "Revert count(where:)"
This reverts commit 779ea19a6a.
Now that SE-0220 has been re-accepted, this adds the `count(where:)`
Sequence method to the standard library.
Even if the member type variable is partially resolved, we still need
to mark inner type variables (if any) as holes because they might not
be connected to anything that could provide contextual type(s).
Resolves: rdar://124549952
Even if protocol is not self-conforming it should be okay to produce
a conformance based on superclass if protocol bounds of the existential
are all marker protocols.
Superclass concrete conformance is wrapped into an inherited conformance
in such cases to reference the existential.
This avoids a crash that could occur when
attempting to query their interface type later,
which could cause us to attempt to type-check
the Decl separately from its enclosing closure.
Eventually we also ought to use this to fill in
ErrorTypes for expressions (since type-checking
ought to only produce typed AST), but I'm leaving
that as future work for now.
rdar://120012473
To maintain source compatibility, SE-0352 does not open existentials
with "self-conforming" type, such as `any Error` or existentials based
on `@objc` protocols. The proposal specified that this behavior would
change in Swift 6. Implement that behavior change, which can be
enabled prior to Swift 6 with the upcoming feature
`ImplicitOpenExistentials` (as documented in SE-0362).
Fixes#70873 / rdar://120902975.
If we fail to build a generic signature (or requirement signature of a
protocol) because of a request cycle or because Knuth-Bendix completion
failed, we would create a placeholder signature with no requirements.
However in a move-only world, a completely unconstrained generic
parameter might generate spurious diagnostics when used in a copyable
way. For this reason, let's outfit these placeholder signatures with
a default set of conformance requirements to Copyable and Escapable.
