Update lang#c layer

autoload/SpaceVim/layers/lang/c.vim

@@ -40,10 +40,16 @@
 
 
 
+let s:use_libclang = 0
+
 function! SpaceVim#layers#lang#c#plugins() abort
   let plugins = []
   if has('nvim')
-    call add(plugins, ['tweekmonster/deoplete-clang2'])
+    if s:use_libclang
+      call add(plugins, ['zchee/deoplete-clang'])
+    else
+      call add(plugins, ['tweekmonster/deoplete-clang2'])
+    endif
   else
     call add(plugins, ['Rip-Rip/clang_complete'])
   endif
@@ -56,6 +62,13 @@ function! SpaceVim#layers#lang#c#config() abort
   call SpaceVim#mapping#space#regesit_lang_mappings('c', funcref('s:language_specified_mappings'))
 endfunction
 
+function! SpaceVim#layers#lang#c#set_variable(var) abort
+  " use clang or libclang
+  let s:use_libclang = get(a:var,
+        \ 'use_libclang',
+        \ 'clang')
+endfunction
+
 function! s:language_specified_mappings() abort
 
   call SpaceVim#mapping#space#langSPC('nmap', ['l','r'],

docs/layers/lang/c.md

@@ -0,0 +1,26 @@
+---
+title: "SpaceVim lang#c layer"
+description: "This layer is for c/c++/object-c development"
+---
+
+# [Layers](https://spacevim.org/layers) > lang#c
+
+
+<!-- vim-markdown-toc GFM -->
+
+- [Description](#description)
+- [Layer Installation](#layer-installation)
+- [Key bindings](#key-bindings)
+
+<!-- vim-markdown-toc -->
+
+## Description
+
+This layer is for c/c++/object-c development.
+
+## Layer Installation
+
+To use this configuration layer, add `SPLayer 'lang#java'` to your custom configuration file.
+
+## Key bindings
+