Inheriting classes from std::

Question

There are many similar questions and I found both pro and against reasons to use this pattern so I am asking this here:

I need to make a JSON implementation in C++ (

Answer 1

• I wouldn't recommend to inherit from STL.

• Due to performance reasons STL standard containers do not have virtual destructors, thus you cannot handle them polymorphically.

• This means that there's no way to use runtime polymorphisim and expect proper desctructors for them.

• Inheriting from STL, although is perfectly allowable, most of the times denotes bad design. I would recommend not following the inherits from way but rather has a way:

---

namespace JSON {
  class JSON { };
  class object : public JSON 
  { 
    std::unordered_map m;

    public:
    // provide interface to access m.
    };
  class Vector : public JSON { 
    std::vector v;

    public:
    // provide interface to access v.
  };
  ...
};