The ITfCandidateListUIElement::GetPageIndex should accept Option<&mut [u32]> instead of &mut [u32] #2184
Description
Summary
The API windows::Win32::UI::TextServices::ITfCandidateListUIElement pub unsafe fn GetPageIndex(&self, pindex: &mut [u32], pupagecnt: *mut u32) -> windows_core::Result<()> currently accept pIndex: &mut [u32].
But according to https://learn.microsoft.com/en-us/windows/win32/api/msctf/nf-msctf-itfcandidatelistuielement-getpageindex, the pIndex can be NULL, which is impossible unless we change the generated Rust code to accept a Option<&mut [u32]>.
Crate manifest
[dependencies]
windows = { version = "0.62.2", features = ["Win32_System_Com", "Win32_UI_TextServices"] }
windows-core = "0.62.2"Crate code
let mut page_count = MaybeUninit::new(0);
// The empty slice doesn't work, the API returns E_INVALIDARG. It must be NULL to let it work.
candidate_list.GetPageIndex(&mut [], page_count.as_mut_ptr()).unwrap();