if path:sub(2,2) == ':' then return true end  -- DOS drive letter followed by volume separator
    local f = path:sub(1,1)
    return f == '/' or f == '\\'
  else
    error('What OS is this? LÖVE reports that the path separator is "'..os_path_separator..'"')
  end
end
function is_relative_path(path)
  return not is_absolute_path(path)
end