相关疑难解决方法(0)

我正在尝试编写一个可以打印堆栈和队列的函数,我的代码如下

template<typename Cont>
void print_container(Cont& cont){
    while(!cont.empty()){
        if(std::is_same<Cont, stack<int>>::value){
            auto elem = cont.top();
            std::cout << elem << '\n';
        } else {
            auto elem = cont.front();
            std::cout << elem << '\n';
        }
        cont.pop();
        std::cout << elem << '\n';
    }
}

int main(int argc, char *argv[])
{
    stack<int> stk;
    stk.push(1);
    stk.push(2);
    stk.push(3);
    queue<int> q;
    q.push(1);
    q.push(2);
    q.push(3);

    std::cout << "print stack" << endl;
    print_container(stk);
    std::cout << "print queue" << endl;
    print_container(q);

    return 0;
}

但它在这里不起作用,错误信息是:

demo_typeof.cpp:35:30: error: no member named 'front' …

  #include <array>
  template<typename T>
  void Func(T Param)
     {
     int Val = 0;
     if (std::is_same<T, bool>::value)
        Val += Param ? 1 : 0;
     }

  int main() 
     {
     std::array<int, 10> A;
     Func(A);
     return 0;
     }

当我用gcc或MSVC编译时,我得到:

Error C2440 '?': cannot convert from 'std::array<int,10>' to 'bool'

不应该编译器甚至不编译,Val += Param ? 1 : 0;因为std::is_same<std::array<int, 10>, bool>::value是0？