title: Comparison of pointers to static constexpr variables in a constant expression
body: <p>In the following code, pointers to <code>static constexpr</code> variables <code>x</code> and <code>y</code> are compared for not-equality:</p>
  <pre><code>int main() {
      static constexpr int x = 1;
      static constexpr int y = 2;
      static_assert( &amp;x != &amp;y );
  }
  </code></pre>
  <p>It works fine in Clang, but not in GCC which prints</p>
  <pre><code>error: non-constant condition for static assertion
  error: '((&amp; x) != (&amp; y))' is not a constant expression
  </code></pre>
  <p>Demo: <a href="https://gcc.godbolt.org/z/3WdqP49Gq" rel="nofollow noreferrer">https://gcc.godbolt.org/z/3WdqP49Gq</a></p>
  <p>Is it just a bug in GCC?</p>