Class member functions not compiling

Question

I decided to write my own Vector class for my library but when I try to compile it using g++ -Wall -std=c++11 -O a.cpp -c -o a.o and read the symbols from the output file using nm a.o I don't see any member functions that I wrote for that class and when I try to link it with a program that uses them I get undefined reference to errors. Here is the a.h file:

template<typename T> class Vector {
    private:
        int vsize;
        const int maxsize=2147483647;
        T* array;
    public:
        Vector();
        ~Vector();
        bool push_back(T t);
        bool pop_back(T* t);
        bool replace(int element, T t);
        bool resize(int newsize);
        bool getP(int element, T* t);
        bool clear();
        T* getArray();
        int size();
        T operator[](int n);
};

And the a.cpp file:

#include <stdlib.h>
#include "a.h"

template<typename T> Vector<T>::Vector() {
    vsize=0;
    array=(T*)malloc(sizeof(T)*vsize);
}
template<typename T> Vector<T>::~Vector() {
    free(array);
}
template<typename T> bool Vector<T>::push_back(T t) {
    if(resize(vsize+1))
        return 1;
    array[vsize-1] = t;
    return 0;
}
template<typename T> bool Vector<T>::pop_back(T* t) {
    *t = array[vsize-1];
    return resize(vsize-1);
}
/*
    Other member function definitons...
*/

I'm using g++ 5.4.0 and nm 2.26.1