iOS 26 doesn't compile

[iMostfa]

WORKAROUND:

Update to latest master branch (until we get a new release)

Cocoapods:

pod 'RealmSwift', :git => 'https://github.com/realm/realm-swift.git', :branch => 'master'
pod 'Realm', :git => 'https://github.com/realm/realm-swift.git', :branch => 'master'

How frequently does the bug occur?

Always

Description

Hi all,

not sure if it's a problem with my configuration, but building for iOS 26 SDK

i get this error:
/Users/mostafa.essam/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk/usr/include/c++/v1/__memory/array_cookie.h:49:28 Cast of an indirect pointer to an Objective-C pointer to 'const size_t *' (aka 'const unsigned long *') is disallowed with ARC

Stacktrace & log output

Can you reproduce the bug?

Always

Reproduction Steps

i'm integrating using Cocoapods

Version

latest version

What Atlas Services are you using?

Local Database only

Are you using encryption?

No

Platform OS and version(s)

26.0

Build environment

Xcode version: 26
Dependency manager and version: Cocoapods

[FelixLisczyk]

I've just compiled Realm from source using Xcode 26 beta by running the command sh build.sh build in the terminal. One adjustment was necessary for a successful build: I added the build setting SWIFT_VERSION_2600 = 5.7; to Configuration/Base.xcconfig. This setting tells the build system which Swift version to use with the new Xcode. My compilation targeted only iOS, watchOS, and macOS platforms. I have not yet tested the resulting binary frameworks within my app.

[iMostfa]

@FelixLisczyk Thanks for the input, can you try to integrate with app ?

eddee.zip

empty project, just with realm, doesn't compile, same error, will be easier to debug

[salvatoreboemia]

Same here

[michalnowak061]

same here

[griffin-stewie]

same here

[michaelloo]

Same here.

I managed to get it compiling with the following 3 changes in RLMCollection.mm

@implementation RLMArrayHolder {
    std::unique_ptr<void *[]> items; // <<--- 1. this
}

NSUInteger RLMUnmanagedFastEnumerate(id collection, NSFastEnumerationState *state) {
    if (state->state != 0) {
        return 0;
    }

    // We need to enumerate a copy of the backing array so that it doesn't
    // reflect changes made during enumeration. This copy has to be autoreleased
    // (since there's nowhere for us to store a strong reference), and uses
    // RLMArrayHolder rather than an NSArray because NSArray doesn't guarantee
    // that it'll use a single contiguous block of memory, and if it doesn't
    // we'd need to forward multiple calls to this method to the same NSArray,
    // which would require holding a reference to it somewhere.
    __autoreleasing RLMArrayHolder *copy = [[RLMArrayHolder alloc] init];
    copy->items = std::make_unique<void *[]>([collection count]); // <<--- 2. this

    NSUInteger i = 0;
    for (id object in collection) {
        copy->items[i++] = (__bridge void *)object; // <<--- 3. this
    }

    state->itemsPtr = (__unsafe_unretained id *)(void *)copy->items.get();
    // needs to point to something valid, but the whole point of this is so
    // that it can't be changed
    state->mutationsPtr = state->extra;
    state->state = i;

    return i;
}
@end

But the tests are failing 😆

Based on my limited understanding of C++ and very dated ARC knowledge, this issue arises when you need to interact with C-style APIs or functions that expect a pointer-to-pointer argument (e.g., void ** or CFTypeRef *, in our case id) to fill in an Objective-C object, while simultaneously managing that object's lifetime with std::unique_ptr

So I've changed the type to void * and used __bridge where the object is set.

I have no idea if this break other things but it seems to work for my app 🤷

[yaotiancheng-ola]

same here

[jhoanarango]

I am glad I am not the only one having this issue.

[neeteshraj]

Same issue.

/Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk/usr/include/c++/v1/__memory/array_cookie.h:49:28 Cast of an indirect pointer to an Objective-C pointer to 'const size_t *' (aka 'const unsigned long *') is disallowed with ARC