the static member variable assignment
<pre><code>#include &lt;iostream&gt;
using namespace std;
class base
{
    static base* mybase;
};
base::mybase = NULL;
char* str = "hello world";
int main()
{
    std::cout&lt;&lt;"hello world"&lt;&lt;std::endl;
    return 0;
}
</code></pre>

<p>why the the line of  code"base::mybase = NULL"  compiler error!  </p>
