Why am I not able to use Vectors in the Dev C/C++ IDE
<p>So, here I wanted to just define a vector and then print the size of the vector's present state, but the compiler in dev c/c++ gives me a compile-time error that "vector was not declared in the scope()"</p>

<p>I wonder if I haven't included the right header files,or something.    </p>

<pre><code>#include&lt;iostream&gt;
using namespace std;
int main()
{   
   vector&lt;int&gt; v(6);               //defining the vector 
   cout&lt;&lt;"Size= "&lt;&lt;v.size();      //printing the present size of the vector
   return 0;
}
</code></pre>