set complete+=b " scan other loaded buffers that are in the buffer list
set complete+=u " scan the unloaded buffers that are in the buffer list
set complete+=t " scan tags
set complete+=b " scan other loaded buffers that are in the buffer list
set complete+=u " scan the unloaded buffers that are in the buffer list
set complete+=t " scan tags
" whether to use a popup menu for Insert mode completion
set completeopt=longest,menuone,preview
" whether to use a popup menu for Insert mode completion
set completeopt=longest,menuone,preview