Seems like the meta-language (compile-time expressions) is now pretty much full fledged.

Long gone days where template meta-programming was the only way to do compile-time code generation and constant checks.... at least that's my impression of the latest language-level features.

I have not worked professionally with c++ for a few years now, but his piece from the article, just seems rather powerful incarnation of the compile-time programming.

  constexpr auto add = [] (int x, int y) {
    auto L = [=] { return x; };
    auto R = [=] { return y; };
    return [=] { return L() + R(); };
  };