title: Why isn't GLsizei defined as unsigned?
body: <p>I was looking up the <code>typedef</code> of <code>GLsizei</code> for the OpenGL ES 1.1 implementation on iOS, and was surprised to find that it was defined as an <code>int</code>. Some quick googling showed that this is normal. (Including on normal OpenGL.)</p>
  
  <p>I was expecting that it would be defined as an <code>unsigned int</code> or <code>size_t</code>. Why is it defined as just a vanilla <code>int</code>?</p>