Function vkAllocateMemory 

pub unsafe extern "system" fn vkAllocateMemory(
    device: VkDevice,
    pAllocateInfo: *const VkMemoryAllocateInfo,
    pAllocator: *const VkAllocationCallbacks,
    pMemory: *mut VkDeviceMemory,
) -> VkResult

Available if built with exported-prototypes.