title: pragma pack an stl containers
body: <p>When I declare such a structure:</p>
  
  <pre><code>#pragma pack(1)
  structure MyStruct{
      uint32_t first;
      uint8_t second;
  };
  #pragma pack()
  </code></pre>
  
  <p>I obviously wish it will take 5 bytes of memory. How will then such a vector behaves:</p>
  
  <pre><code>std::vector&lt;MyStruct&gt; MyVec;
  </code></pre>
  
  <p>Or such a map:</p>
  
  <pre><code>std::map&lt;MyStruct&gt; MyMap;
  </code></pre>
  
  <p>Will they obey requested alignment? Can I force STL structures to do that?</p>