shared_pod

shared_pod.cc

#include <iostream>
using std::cin;
using std::cout;
using std::cerr;
using std::endl;



#include <type_traits>
#include <memory>

namespace tue
{
	struct default_tag {};

	template <class T, class TAG=default_tag>
	struct shared_pod
	{
		static_assert(std::is_pod<T>{}, "T must be a POD");
		static_assert(!std::is_same<T, bool>{}, "T can not be bool");

		using element_type = T;
		using tag = TAG;

	private:
		using sptr = std::shared_ptr<element_type>;
		sptr element;

	public:
		shared_pod() = default;

		template <class DELETER>
		shared_pod(element_type e, DELETER d)
			: element {
				new element_type(e),
				[d = std::move(d)](auto x) { d(*x); delete x; }
			}
		{}

		operator bool () const { return element; }
		operator element_type () const { return *element; }
	};
}


int main()
{
	auto deleter = [](auto x) { cout << x << endl; };

	tue::shared_pod<int> x;
	tue::shared_pod<int> y;
	x = {3, deleter};
	x = {4, deleter};
	y = x;
	x = {5, deleter};
	cout << ">> " << int(x) << endl;
	cout << "----" << endl;
}