Honestly, just about anything is going to be faster, productivity-wise, than C++. When you stop having to think about how you're going to structure your inheritance and classes, you--shockingly--get things done. But more metaprogramming is not the answer. And I've used Scheme since 2002 or so. I'm implemented Scheme interpreters and compilers. But I'm no longer a cheerleader for macros and call/cc or Scheme (or Lisp, for that matter).
You know what gets things done and makes things easy to maintain? Boring ass code. IF statements. FOR loops. I mostly use Perl today. It doesn't get in the way. But getting things done is not trendy. That's where we are today.