Vulkan.cppm fails to compile on 1.4.304.0

[Hisukedema]

When compiling in Visual Studio (MSVC), the following error is produced:

------ Build started: Project: VulkanHppModuleLib, Configuration: Debug x64 ------
Scanning sources for module dependencies...
Compiling...
vulkan.cppm
C:\VulkanSDK\1.4.304.0\Include\vulkan\vulkan.cppm(2701,31): error C2039: 'PFN_VoidFunction': is not a member of 'vk'
C:\VulkanSDK\1.4.304.0\Include\vulkan\vulkan.cppm(29,18): see declaration of 'vk'
C:\VulkanSDK\1.4.304.0\Include\vulkan\vulkan.cppm(2701,3): error C2873: 'PFN_VoidFunction': symbol cannot be used in a using-declaration
Done building project "VulkanHppModuleLib.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ==========

Commenting out line 2701 of Vulkan.cppm fixes the issue and allows compilation.

The visual studio project was generated with this cmake code:

function (VE_Create_Vulkan_hpp_module)

    # find Vulkan SDK
    find_package( Vulkan REQUIRED )

    # Require Vulkan version ≥ 1.3.256 (earliest version when the Vulkan module was available)
    if( ${Vulkan_VERSION} VERSION_LESS "1.3.256" )
      message( FATAL_ERROR "Minimum required Vulkan version for C++ modules is 1.3.256. "
               "Found ${Vulkan_VERSION}."
      )
    endif()

    message(STATUS "Vulkan_INCLUDE_DIR='${Vulkan_INCLUDE_DIR}'")

    add_library( VulkanHppModuleLib )

    target_sources( VulkanHppModuleLib PRIVATE
     FILE_SET CXX_MODULES
     BASE_DIRS ${Vulkan_INCLUDE_DIR}
     FILES "${Vulkan_INCLUDE_DIR}/vulkan/vulkan.cppm"
    )

    target_include_directories(VulkanHppModuleLib
            PUBLIC 
                "${Vulkan_INCLUDE_DIR}"
    )

    target_compile_features( VulkanHppModuleLib PUBLIC cxx_std_23 )
    target_link_libraries( VulkanHppModuleLib PUBLIC Vulkan::Vulkan )

endfunction()

[noir-nik]

I can confrm this. The module only compiles when line 2701 is commented or replaced with

using ::PFN_vkVoidFunction;

The error code generated with clang:

D:/VulkanSDK/1.4.304.0/Include/vulkan/vulkan.cppm:2701:9: error: no member named 'PFN_VoidFunction' in namespace 'vk'; did you mean '::PFN_vkVoidFunction'?
 2701 |   using VULKAN_HPP_NAMESPACE::PFN_VoidFunction;
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |         ::PFN_vkVoidFunction
D:\VulkanSDK\1.4.304.0\Include/vulkan/vulkan_hpp_macros.hpp:220:32: note: expanded from macro 'VULKAN_HPP_NAMESPACE'
  220 | #  define VULKAN_HPP_NAMESPACE vk
      |                                ^
D:\VulkanSDK\1.4.304.0\Include/vulkan/vulkan_core.h:3122:26: note: '::PFN_vkVoidFunction' declared here
 3122 | typedef void (VKAPI_PTR *PFN_vkVoidFunction)(void);

[asuessenbach]

Or as a hotfix add this to vulkan_handles.hpp:

typedef void( VKAPI_PTR * PFN_VoidFunction )();

This missing typedef has been added by #2033, but apparently that change hasn't made it into the 304 release of the VulkanSDK. I'm so sorry about that!