C++ delegate parameters are already optional

[kennykerr]

The param "lptimerfunc" type "TIMERPROC" of SetTimer is option itself, I think it is repeated.

Originally posted by @liqh99em in #3368 (comment)

[kennykerr]

An example from 0.58 of the windows crate:

use windows::{Win32::Foundation::*, Win32::System::Console::*};

fn main() {
    unsafe {
        SetConsoleCtrlHandler(Some(callback), true).unwrap();
    }
}

unsafe extern "system" fn callback(_ctrltype: u32) -> BOOL {
    BOOL(1)
}

With 0.59 the callback must be double wrapped:

SetConsoleCtrlHandler(Some(Some(callback)), true).unwrap();