title: Unique copy of vector<unique_ptr>
body: <p>I have a class object which contains a <code>vector&lt;unique_ptr&gt;</code>. I want a copy of this object to run non-const functions on. The original copy must remain <strong>const</strong>.</p>
  
  <p>What would the copy constructor for such a class look like?</p>
  
  <pre><code>class Foo{
  public:
   Foo(const Foo&amp; other): ??? {}
  
   std::vector&lt;std::unique_ptr&gt; ptrs;
  };
  </code></pre>