#include <iostream>

#include <vector>

using namespace std;

using fun=void (*)(int, int);

void example(int, int) {}

template<typename T>

struct Container {

using value_type=T; // 等价于typedef T value_type;

};

template<typename Cn>

void func2(const Cn &cn) {

typename Cn::value_type n;

}

template<typename CharT>

using string=basic_string<CharT, char_traits<CharT>>;

int main() {

fun fn = example; // 函数指针

return 0;

}