patch 8.2.0512: Vim9: no optional arguments in func type Commit: https://github.com/vim/vim/commit/5deeb3f1f9db4eabd36e99cbf857fe376eb37e10 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Apr 5 17:08:17 2020 +0200 patch 8.2.0512: Vim9: no optional arguments in func type Problem: Vim9: no optional arguments in func type. Solution: Check for question mark after type. Find function reference without function().

function Test_Comparators()
  try
    let oldisident=&isident
    set isident+=#
    call assert_equal(1, 1 is#1)
  finally
    let &isident=oldisident
  endtry
endfunction