When setting the option g:clang_auto to 0 you have to set it before the plugin is loaded otherwise it won't have an effect, and will auto complete no matter what.
This is because the plugin uses mappings I.E
if g:clang_auto " Auto completion
inoremap <expr> <buffer> . <SID>CompleteDot()
inoremap <expr> <buffer> > <SID>CompleteArrow()
if &filetype == 'cpp'
inoremap <expr> <buffer> : <SID>CompleteColon()
endif
endif
When setting the option
g:clang_auto
to 0 you have to set it before the plugin is loaded otherwise it won't have an effect, and will auto complete no matter what.This is because the plugin uses mappings I.E