3a200dee has a logic bug where we tried to conform C++ iterator types to `UnsafeCxxContiguousIterator` protocol based on their nested type called `iterator_category`. The C++20 standard says we should rely on `iterator_concept` instead.
https://en.cppreference.com/w/cpp/iterator/iterator_tags#Iterator_concept
Despite what the name suggests, we are not actually using C++ concepts in this change.
rdar://137877849
This adds a pair of Swift protocols that represents C++ iterator types conforming to `std::contiguous_iterator_tag` requirements. These are random access iterators that guarantee that the values are stored in consequent memory addresses.
This will be used to optimize usage of C++ containers such as `std::vector` from Swift, for instance, by providing an overload of `withContiguousStorageIfAvailable` for contiguous containers.
rdar://137877849
This conforms mutable C++ container types, such as `std::vector`, to `MutableCollection` via a new overlay protocol `CxxMutableRandomAccessCollection`.
rdar://134531554
These x-refs might not be resolvable using regular lookup from the 'std' module as they could be instantiated/synthesized
by the clang importer. Augment the lookup logic in that case to try clang importer lookup logic that is used during
the conformance to the C++ iterator protocol.
This cleans up the C++ iteration tests and makes sure that we test the setup where a C++ iterator and a C++ collection are defined in different Clang modules.
C++ `operator bool()` is currently imported into Swift as `__convertToBool()`, which shouldn't be used by clients directly.
This adds a new protocol into the C++ stdlib overlay: `CxxConvertibleToBool`, along with an intitializer for `Swift.Bool` taking an instance of `CxxConvertibleToBool`.
rdar://115074954
This fixes a compiler error when building SwiftCompilerSources in hosttools mode with a recent Xcode.
```
<unknown>:0: error: calling a private constructor of class 'clang::StmtIterator'
swift/llvm-project/clang/include/clang/AST/StmtIterator.h:137:3: note: declared private here
StmtIterator(const StmtIteratorBase &RHS)
^
```
rdar://113514872
I discovered this when experimenting with `std::map::iterator`, which has a const overload of `operator*` that returns a non-const reference, and does not have a const overload of `operator*`.
rdar://112471779
This is an inheritor of the existing `UnsafeCxxInputIterator` protocol, with the only difference being the ability to mutate `var pointee` via a non-const `operator*()`.
This is needed to support mutable subscripts for `std::map` via `CxxDictionary`.
rdar://105399019
C++ `T& operator*()` is mapped to a Swift computed property `var pointee: T`.
Previously `var pointee` only had a getter, after this change it will also have a setter if the C++ type declares an overload of `operator*` that returns a mutable reference.
rdar://112471779
This fixes the automatic `std::unordered_map` conformance to CxxDictionary on Linux. Previously `std::unordered_map::const_iterator` was not auto-conformed to UnsafeCxxInputIterator because its `operator==` is defined on a templated base class of `const_iterator`.
rdar://105220600
C++ iterator types are often templated, and sometimes declare `operator==` as a non-member templated function. In libc++, an example of this is `__wrap_iter` which is used as an iterator type for `std::vector` and `std::string`.
We don't currently import templated non-member operators into Swift, however, we still want to support common C++ iterator patterns.
This change adds logic to instantiate templated non-member `operator==` for types that define `iterator_category` and are therefore likely to be valid iterator types.
rdar://97915515
If an operator is declared as a method of a templated class, we were failing to look it up during auto-conformance to `UnsafeCxxInputIterator`.
This fixes `Interop/Cxx/stdlib/use-std-map.swift` on Ubuntu.
rdar://102420290
This fixes a couple cases of cases where a malformed C++ iterator type would trigger an assertion in ClangImporter: `Assertion failed: (Val && "isa<> used on a null pointer")`.
This makes ClangImporter automatically conform C++ sequence types to `Cxx.UnsafeCxxInputIterator` protocol.
We consider a C++ type to be a random access iterator type if conforms to `UnsafeCxxInputIterator`, and additionally defines `operator-` and `operator+=`.
This helps to bridge C++ random access collections, such as `std::vector` and `std::string`, to Swift by conforming them to `Swift.RandomAccessCollection`
To determine whether to conform a C++ type to `CxxSequence` protocol automatically, ClangImporter checks if the corresponding iterator type conforms to `UnsafeCxxInputIterator`.
This logic had false-positives, e.g. `Optional<OpaquePointer>` was treated as if it conforms to `UnsafeCxxInputIterator` while it actually doesn't. This happened because `lookupConformance` returned a conformance with a conditional requirement (`Wrapped : UnsafeCxxInputIterator`) that is not satisfied for `OpaquePointer`.
rdar://100265664
This makes ClangImporter automatically conform C++ sequence types to `Cxx.CxxSequence` protocol.
We consider a C++ type to be a sequence type if it defines `begin()` & `end()` methods that return iterators of the same type which conforms to `UnsafeCxxInputIterator`.
Previosly we didn't detect `func ==` that was declared out-of-class when synthesizing conformaces to `UnsafeCxxInputIterator`. Now we do.
rdar://96235368
This teaches ClangImporter to synthesize conformances of C++ iterator types to `UnsafeCxxInputIterator` protocol from the `Cxx` module.
We consider a C++ type to be an iterator if it defines a subtype (usually a typedef or a using decl) called `iterator_category` that inherits from `std::input_iterator_tag`.
rdar://96235368
This change adds basic helper protocols and structs that are going to be used for making C++ sequences and collection safe and Swifty by adding conformances to `Swift.Sequence`, `Swift.Collection`, etc.
This is not meant to be a final design.
