title: Why this built-in type has error when compiling?
body: <pre><code>#include &lt;stdio.h&gt;
  #include &lt;wctype.h&gt;
  int main ()
  {
    wchar_t c;
  
    return 0;
  }
  </code></pre>
  <hr />
  <pre><code>In file included from /usr/include/wctype.h:38:0,
                   from main.cpp:2:
  /usr/include/x86_64-linux-gnu/bits/wctype-wchar.h:3:12: error: stray ‘`’ in program
      none of `iswcntrl', `iswdigit', `iswpunct', or `iswspace' is true.  */
              ^
  /usr/include/x86_64-linux-gnu/bits/wctype-wchar.h:3:36: error: stray ‘`’ in program
      none of `iswcntrl', `iswdigit', `iswpunct', or `iswspace' is true.  */
                                      ^
  /usr/include/x86_64-linux-gnu/bits/wctype-wchar.h:60:2: error: #endif without #if
   #endif /* bits/wctype-wchar.h.  */
  </code></pre>
  <p>OS: <code>Ubuntu 18.04</code></p>
  <p>GCC: <code>7.5.0</code></p>
  <p>I think wchar_t is a std type... So maybe I need to update something like gcc?</p>