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POShould I implement a smart pointer type for array and support arithmetic operators?
 

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  1. POShould I implement a smart pointer type for array and support arithmetic operators?
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    <p>I heard smart pointers like std::shared_ptr, std::unique_ptr (and in addition array classes like std::array boost::shared_array) but those pointers don't support arithmetic operations.</p> <p>I want a smart pointer type only for array that acts like normal pointers, in other words, it can have ++p, p++, p--, p+n, n+p, *p, p[n], p-> operators etc.</p> <p>so I wrote a class ArrayPtr:</p> <pre><code>template &lt;typename T&gt; class ArrayPtr final { public: typedef size_t size_type; ArrayPtr() noexcept; ArrayPtr(nullptr_t) noexcept; ArrayPtr(T p[], size_type size); ArrayPtr(const ArrayPtr &amp;p); ~ArrayPtr(); ArrayPtr &amp; operator = (const ArrayPtr &amp;p); ArrayPtr &amp; operator += (size_type offset); ArrayPtr &amp; operator -= (size_type offset); T &amp; operator * () const noexcept; // dereference *p T &amp; operator [] (size_type index) const;// dereference p[index] T * operator -&gt; () const noexcept; // dereference p-&gt; ArrayPtr operator + (size_type offset) const; ArrayPtr operator - (size_type offset) const; ArrayPtr &amp; operator ++ (); // prefix ++p ArrayPtr operator ++ (int); // suffix p++ ArrayPtr &amp; operator -- (); // prefix --p ArrayPtr operator -- (int); // suffix p-- inline T * get() const noexcept; inline T * getFirst() const noexcept; inline T * getLast() const noexcept; inline size_type getPos() const noexcept; inline size_type getSize() const noexcept; private: void addPtr(T p[], size_type size); void removePtr(T p[]); private: T *m_ptr; size_type m_pos; size_type m_size; struct PtrCounter { T *ptr; size_type size; size_type count; }; static vector&lt;PtrCounter&gt; sm_ptrCounters; }; </code></pre> <p>It act like shared_ptr, but to make a dynamic array you should do: <code>ArrayPtr p(new int[8], 8)</code> When accessing array elements you can use <code>p[3] = 10;</code> or <code>*(p+4) = 20;</code></p> <p>And you can also have <code>p++</code> and <code>p += 5</code></p> <p>When you try to give an index out of the array's bounds, it throw an OutOfBound exception.</p> <p>I use static member sm_ptrCounters to record the number of pointers that points to the same array.</p> <p>I can't tell the advantage of doing this, I'm just a nerd that want things to be consistent. And I'd like to know why shouldn't I do this (since no c++ library provide this feature).</p> <p>Any suggestion is welcome :)</p>
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    1. USLinlix
    1. USLinlix
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    1. COThat's what iterators are for (act like a pointer on a standard container or array)! You don't need to implement this yourself.
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      1. POShould I implement a smart pointer type for array and support arithmetic operators?
      1. USπάντα ῥεῖ
    2. COAlso, this helper class is not so *smart*, because you'd have to clean memory by yourself.
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      1. POShould I implement a smart pointer type for array and support arithmetic operators?
      1. USSChepurin
    3. COThe `inline` specifier is not needed, member functions are inline by default.
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      1. POShould I implement a smart pointer type for array and support arithmetic operators?
      1. USManu343726
 

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