I’m trying to create a templated C++ library. The header file of the library is as follows:

// header.h
#include <iostream>

template<typename T>
class MyClass
{
        private:
                T value;
        
        public:
                MyClass(): value(0) {};
                void set(T v);
                void print();
};

The implementation of the library source code is this:

// lib.cc
#include <header.h>

template<typename T>
void MyClass<T>::set(T v)
{
        this->value = v;
}


template<typename T>
void MyClass<T>::print()
{
        std::cout << this->value << std::endl;
}

And the code which uses this library is this:

// test.cc
#include <header.h>

int main()
{
        MyClass<int> obj;
        obj.set(10);
        obj.print();
        return 0;
}

I’m compiling my code using g++ via g++ -I. lib.cc test.cc. Moreover, all the three files are in the same directory. However, when I try to compile my code, I get the following linker errors:

/usr/bin/ld: /tmp/ccbvMPJe.o: in function `main':
test.cc:(.text+0x34): undefined reference to `MyClass<int>::set(int)'
/usr/bin/ld: test.cc:(.text+0x40): undefined reference to `MyClass<int>::print()'
collect2: error: ld returned 1 exit status

Why can’t the linker find the implementations of set and print. It should be able to find the implementation of these two functions in the lib.cc file. What am I doing wrong?