[Bug]: Importing a module with a Module-Swift.h fails to compile by default in C++

[leptos-null]

What are the steps to reproduce this issue?

Minimum project to reproduce:

• Makefile

  TARGET := iphone:clang:latest:14.0
  THEOS_PACKAGE_SCHEME := rootless
  
  include $(THEOS)/makefiles/common.mk
  
  LIBRARY_NAME = TestIssue
  
  TestIssue_FILES = TestIssue.mm
  TestIssue_CFLAGS = -fobjc-arc
  TestIssue_EXTRA_FRAMEWORKS = Cephei
  
  include $(THEOS_MAKE_PATH)/library.mk

• TestIssue.mm:

  #import <Cephei/Cephei.h>

1. Run make

What happens?

The project fails to compile.

What were you expecting to happen?

The project to compile without warnings or errors.

Perhaps Theos can select a std version that is high enough to handle the code in these headers.

Paste any relevant logs, error output, etc.

> Making all for library TestIssue…
==> Compiling TestIssue.mm (arm64)…
While building module 'Cephei' imported from TestIssue.mm:1:
In file included from <module-includes>:2:
${THEOS}/vendor/lib/iphone/rootless/Cephei.framework/Headers/Cephei-Swift.h:221:13: error: alias declarations are a C++11 extension [-Werror,-Wc++11-extensions]
using Int = ptrdiff_t;
            ^
${THEOS}/vendor/lib/iphone/rootless/Cephei.framework/Headers/Cephei-Swift.h:222:14: error: alias declarations are a C++11 extension [-Werror,-Wc++11-extensions]
using UInt = size_t;
             ^

Additional context

Settings TestIssue_CCFLAGS = -std=c++11 results in the project compiling without warnings or errors.

The lines in question are
https://github.com/theos/lib/blob/a27acf4/iphone/rootless/Cephei.framework/Headers/Cephei-Swift.h#L217-L225

What OS are you seeing the problem on?

macOS

What OS version does it have installed?

macOS 13.4.1

What toolchain and version are you using?

Xcode 14.3

Which SDK version are you using?

iOS 16.4

What OS is your client device running?

iOS

What OS version does it have installed?

N/A

Which device model is it?

N/A

Which jailbreak is it using (if relevant)?

N/A