#include <cassert>
#include <vector>

#include <tbb/parallel_reduce.h>
#include <tbb/parallel_scan.h>

int main()
{
	std::vector <int> vec;
	const int len = 34479;

	struct non_trivial_range : tbb::blocked_range <decltype(vec)::iterator>
	{
		using non_trivial_range::blocked_range::blocked_range;
		
		~non_trivial_range()
		{
			assert( cookie == 0xc001c001 );
			cookie = 0xdeadbeef;
		}
		unsigned cookie = 0xc001c001;
	};

	vec.assign( len, 1 );
	
	// this works fine
	int s = tbb::parallel_reduce( non_trivial_range{ vec.begin(), vec.end() }, 0, [&]( const auto & rng, int acc )
	{
		for (int p : rng) acc += p; // work is irrelevant

		return acc;
	}, std::plus<>() );
	assert( s == len );

	// this fails eventually
	for (int i = 0; i < 1000; ++i)
	{
		s = tbb::parallel_scan( non_trivial_range{ vec.begin(), vec.end() }, 0, [&]( const auto & rng, int acc, auto is_final )
		{
			for (int p : rng) acc += p; // work is irrelevant

			return acc;
		}, std::plus<>() );
		assert( s == len );
	}
	return s;
}