Why we can't include std headers within a namespace in C++
<p>The following code will cause compile errors in g++4.4:</p>

<pre><code>// File test.cpp
namespace A
{
    #include &lt;iostream&gt;
}

int main()
{
    return 0;
}
</code></pre>

<p>I have this requirement because some third party library comes without namespace protected, and if I directly include these headers, my namespace is polluted.<br>
As a result, I tried to create namespaces for those libraries, but if the library includes some "std headers" the above approach will fail.</p>

<p>Can anybody help?</p>

<p>Thank You!</p>
