I am trying to create a static library of files with .inl extension, but getting failed. If I change the extension to .cpp then it builds.

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.0)
project(CarSimulator VERSION 0.1.0 LANGUAGES C CXX)

include(CTest)
enable_testing()

add_library(printer
   print.inl print.hpp
)
set_property(TARGET printer PROPERTY CXX_STANDARD 20)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)

print.hpp

#ifndef PRINT_H
#define PRINT_H

template<typename T>
void print(const T& t);

#include "print.cpp"

#endif

print.inl

#include <iostream>

template<typename T>
void print(const T& t) {
   std::cout << t << std::endl;
}

Error

CMake Error: Cannot determine link language for target "printer".
CMake Error: CMake can not determine linker language for target: printer
-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.