C4368 Error C++ Windows Forms declaration vector

I have error in VS2015. Why I cannot define my vector? C4368: cannot define 'table' as a member of managed 'Example' mixed types are not supported.

#pragma once
#include<iostream>
#include <cstdio>
#include <vector>
using namespace std;
ref class Example
{
private:
    vector <int> table;
public:
    Example();
};