Xcode中的未定义符号来自构造函数和重构器，即使我在代码中编写了定义，仍然无效

Question

我正在尝试定义自己的Queue类，但编译器会生成“ld，undefined symbols”，其中包含构造函数和重构器。 但是，我已经在代码中写了定义和声明。我也一起建造它们。所以我不知道我错在哪里。

感谢您帮助我，我真的不知道如何处理它。

这是mt标题：

#ifndef __C4E2A1_Queue_Container__Queue__
#define __C4E2A1_Queue_Container__Queue__

#include <iostream>
#include <stdexcept>
#include <cassert>

    template <typename T> class Queue
    {
    public:
        Queue();
        ~Queue();
        Queue(const Queue &);
        Queue &operator=(const Queue &);
        void push(const T &);
        void pop();
        T &front();
        const T &front() const;
        bool empty() const;
        size_t size() const;

    private:
        T *v_;
        T *vhead_;      // for queue's head and tail FIFO
        size_t vsize_;
        size_t vused_;  // once the place has been written, it's used
        size_t vpopped_; // when pop from head of the queue, log it.

    };

#endif /* defined(__C4E2A1_Queue_Container__Queue__) */

这是我的cpp

#include "Queue.h"

template <typename T>
Queue<T>::Queue()
: v_(0),
vsize_(10),
vhead_(0),
vused_(0),    // nothing used
vpopped_(0)   // nothing popped
{
    v_ = new T[vsize_];
    vhead_ = v_;
}

template <typename T>
Queue<T>::~Queue()
{
    delete [] v_;
}

template <typename T>
T *
newCopy(const T *src, size_t srcsize, size_t destsize)
{
    assert(destsize >= srcsize);
    T *dest = new T[destsize];
    try
    {
        copy(src, src + srcsize, dest);
    }
    catch (...)
    {
        delete []  dest;
        throw ;
    }
    return dest;
}

template <typename T>
Queue<T>::Queue(const Queue &other)
    : v_(newCopy(other.v_,
                 other.vsize_,
                 other.vsize_)),
    vhead_(other.vhead_),
    vsize_(other.vsize_),
    vused_(other.vused_),
    vpopped_(other.vpopped_)
{
}

template <typename T>
Queue<T> &
Queue<T>::operator=(const Queue<T> &other)
{
    if (this != &other) {
        T *v_new = newCopy(other.v_,
                           other.vsize_,
                           other.vsize_);

    delete[] v_;
    v_ = v_new;
    vhead_ = other.vhead_;
    vpopped_ = other.vpopped;
    vsize_ = other.vsize_;
    vused_ = other.vused_;
    }

    return *this;
}

template <typename T>
size_t
Queue<T>::size() const
{
    return (vused_ - vpopped_);
}

template <typename T>
void
Queue<T>::push(const T& t)
{
    if (vused_ == vsize_) {
        size_t vsize_new = vsize_ * 2 + 1;
        T *v_new = newCopy(vhead_, (vsize_ - vpopped_), vsize_new);
        delete[] v_;
        v_ = v_new;
        vhead_ = v_new;
        vpopped_ = 0;
        vsize_ = vsize_new;
    }
    // put the elem into the queue
    v_[vused_] = t;
    ++vused_;

    // show where is the tail
    //++vtail_;
}

template <typename T>
void
Queue<T>::pop()
{
    if (vused_ == 0) {
        throw std::logic_error("pop from empty queue");
    }
    else
    {
        // let the start of the queue to the next elem
        ++vhead_;
        // pop this one out
        ++vpopped_;
    }
}

template <typename T>
T &
Queue<T>::front()
{
    if (vused_ == 0) {
        throw std::logic_error("empty queue");
    }
    else
    {
        return vhead_;
    }
}

template <typename T>
const T&
Queue<T>::front() const
{
    if (vused_ == 0) {
        throw std::logic_error("empty queue");
    }
    else
    {
        return *vhead_;
    }
}

template <typename T>
bool
Queue<T>::empty() const
{
    // if three elem come int and three get popped
    // it's empty
    if ((vused_ - vpopped_) == 0)
        return true;
    else
        return false;
}

这是主要的，只是为了测试Queue类。

#include <iostream>
#include "Queue.h"

int main()
{

    Queue<int> test0 ;

    //test0.push(10);

    //std::cout << test0.size();

    return 0;
}

Xcode的错误是：

Undefined symbols for architecture x86_64:
  "Queue<int>::Queue()", referenced from:
      _main in main.o
  "Queue<int>::~Queue()", referenced from:
      _main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)