togglecomment.vim

" source: https://stackoverflow.com/a/24046914/2571881
let s:comment_map = {
    \   "c": '\/\/',
    \   "cpp": '\/\/',
    \   "go": '\/\/',
    \   "java": '\/\/',
    \   "javascript": '\/\/',
    \   "lua": '--',
    \   "scala": '\/\/',
    \   "php": '\/\/',
    \   "python": '#',
    \   "ruby": '#',
    \   "rust": '\/\/',
    \   "sh": '#',
    \   "desktop": '#',
    \   "fstab": '#',
    \   "conf": '#',
    \   "profile": '#',
    \   "bashrc": '#',
    \   "bash_profile": '#',
    \   "mail": '>',
    \   "eml": '>',
    \   "bat": 'REM',
    \   "ahk": ';',
    \   "vim": '"',
    \   "tex": '%',
    \ }

function! ToggleComment()
    if has_key(s:comment_map, &filetype)
        let comment_leader = s:comment_map[&filetype]
        if getline('.') =~ '^\s*$'
            " Skip empty line
            return
        endif
        if getline('.') =~ '^\s*' . comment_leader
            " Uncomment the line
            execute 'silent s/\v\s*\zs' . comment_leader . '\s*\ze//'
        else
            " Comment the line
            execute 'silent s/\v^(\s*)/\1' . comment_leader . ' /'
        endif
    else
        echo "No comment leader found for filetype"
    endif
endfunction

nnoremap <Leader>t :call ToggleComment()<CR>
vnoremap <Leader>t :call ToggleComment()<CR>

@backermanbd @OrionRandD I just found vim-commentary. I will probably use that going forward instead of maintaining this. It has better community support, isn't much larger than this, and uses Vim's 'commentstring' option instead of a list of hard coded file types so it automatically works with a lot more languages.

@dave-kennedy I tried vim-commentary. But didn't like it though.
I just wanted voyeg3r & your code to put comment out signs at the first of each line

like this cpp code

// #include <iostream>
// using namespace std;

// int main(){
//     cout << "hello world";
// }

@dave-kennedy please help me add the feature..

@backermanbd @dave-kennedy
+1, CPP developers need this feature