template<typename T>

static void push(T const& v) {

std::vector<T>& stack = get_stack<T>();

stack.push_back(v);

}

template<typename T>

static T pop() {

std::vector<T>& stack = get_stack<T>();

T v = stack.back();

stack.pop_back();

return v;

}

private:

template<typename T>

static std::vector<T>& get_stack() {

static std::vector<T> stack = {};

return stack;

}