Function get_instance_proc_addr 

pub unsafe fn get_instance_proc_addr(
    instance: &Instance,
    name: &CStr,
) -> PFN_vkVoidFunction

Resolve an instance command using this instance’s retained loader.

Safety

Cast to the command’s exact ABI, obey its enabled-version/extension requirements and keep the instance and native library alive during use.

Khronos reference: vkGetInstanceProcAddr