title: wglGetProcAddress returning NULL
body: <p>I am using <code>wlgGetProcAddress</code> to get functions using a context created with <code>wglCreateContext</code>.  I have set the context with <code>wglMakeCurrent</code>.  I get a valid function pointer for <code>glGetStringi</code>, but I get <code>NULL</code> for <code>glGetString</code>.  I thought that <code>glGetString</code> and <code>glGetStringi</code> were introduced in the same version of OpenGL (1.0).  Any ideas why I am getting this <code>NULL</code>?</p>
  
  <pre><code>const GLubyte* (*glGetString)(GLenum);
  const GLubyte* (*glGetStringi)(GLenum, GLuint);
  glGetString = reinterpret_cast&lt;decltype(glGetString)&gt;(wglGetProcAddress("glGetString"));
  glGetStringi = reinterpret_cast&lt;decltype(glGetStringi)&gt;(wglGetProcAddress("glGetStringi"));
  </code></pre>
  
  <p>In case it matters, I have a Radeon HD 7950 with driver version 13.251.0.0.</p>