cpp-descriptive-pointers/const_ptr.hpp

//
//  const_ptr.hpp
//  pointers
//
//  Created by Sam Jaffe on 1/5/17.
//

#pragma once
#include <memory>

#include "pointer_fwd.hpp"

template <typename P>
class const_ptr {
public:
  using element_type = typename std::pointer_traits<T>::element_type;
  using pointer = element_type const *;
  using reference = element_type const &;

  const_ptr() : _ptr(nullptr) {}
  const_ptr(T const & p) : _ptr(p) {}
  const_ptr(T && p) : _ptr(std::move(p)) {}
  
  template <typename Y>
  explicit operator const_ptr<Y>() & {
    return _ptr;
  }

  reference operator*() { return *_ptr; }
  pointer get() { return std::addressof(operator*()); }
  pointer operator->() { return get(); }
private:
  P _ptr;
};