title: Can't use std::vector in place of std::array on QOpenGLBuffer::allocate
body: <p>I'm working with OpenGl with Qt and I'm allocating a buffer with std::array, I want to replace it with std::vector, it should work almost the same way, but it doesn't work at all, just black screen.</p>
  
  <p>Vertex is just a class with six floats (x,y,z, r,g,b) and few methods</p>
  
  <p>declaration of vertexes</p>
  
  <pre class="lang-cpp prettyprint-override"><code>//works
  std::array&lt;Vertex, 12&gt; vertexes = {
      VERTEX_0, VERTEX_2, VERTEX_TOP,
      VERTEX_2, VERTEX_1, VERTEX_TOP,
      VERTEX_1, VERTEX_0, VERTEX_TOP,
      VERTEX_0, VERTEX_1, VERTEX_2,
  };
  
  //doesn't work
  std::vector&lt;Vertex&gt; vertexes = {
      VERTEX_0, VERTEX_2, VERTEX_TOP,
      VERTEX_2, VERTEX_1, VERTEX_TOP,
      VERTEX_1, VERTEX_0, VERTEX_TOP,
      VERTEX_0, VERTEX_1, VERTEX_2,
  };
  </code></pre>
  
  <p>buffer allocation</p>
  
  <pre class="lang-cpp prettyprint-override"><code>m_vertex.allocate(vertexes.data(), sizeof(Vertex) * vertexes.size());
  </code></pre>