Function vk_mem_alloc::ffi::vmaSetAllocationUserData

pub unsafe extern "C" fn vmaSetAllocationUserData(
    allocator: VmaAllocator,
    allocation: VmaAllocation,
    pUserData: *mut c_void
)

\brief Sets pUserData in given allocation to new value.

The value of pointer pUserData is copied to allocation’s pUserData. It is opaque, so you can use it however you want - e.g. as a pointer, ordinal number or some handle to you own data.