Undefined reference to a custom class's method in C++

Question

I'm new at C++. I'm trying to re-implement the container vector. So far I have had a header file named vector.hpp:

    #ifndef VECTOR_HPP
    #define VECTOR_HPP
    
    #include <iostream>
    
    namespace ft
    {
        template <typename T>
        class vector
        {
            public:
                vector(void);
                ~vector(void);
            private:
                unsigned int _size;
        };
    } 
    #endif

And a source file named vector.cpp

#include "vector.hpp"

template <typename T>
ft::vector<T>::vector(void): _size(0)
{ std::cout << "Constructor called\n";}

template <typename T>
ft::vector<T>::~vector(void) 
{ std::cout << "Deconstructor called\n";}

Then my main.cpp

#include <iostream>
#include "vector.hpp"

int main(void)
{
    ft::vector<int> vect_int;
    return(0);
}

Then I compile with: c++ main.cpp vector.cpp and it gives the error which I don't know why. Thanks for your help!

/tmp/ccVgRWqs.o: In function `main':
main.cpp:(.text+0x20): undefined reference to `ft::vector<int>::vector()'
main.cpp:(.text+0x31): undefined reference to `ft::vector<int>::~vector()'
collect2: error: ld returned 1 exit status