A minimal example for creating, compiling and using a dynamic library in C++.

example_dynamic_library_in_c++.md

A minimal example for creating, compiling and using a dynamic library in C++.

1. Create a test library

// test.h
#pragma once 
int add(int a, int b);
int mult(int a, int b);

// test.cc
int add(int a, int b){ return a+b; }
int mult(int a, int b){ return a*b; }

2. Compile the test library

$ g++ -shared -fPIC -o libtest.so test.cc

3. Use the test library in a test project

// main.cc
#include <iostream>
#include "test.h"
int main()
{
    std::cout << "1 + 3 = " << add(1, 3) << std::endl;
    std::cout << "1 * 3 = " << mult(1, 3) << std::endl;
}

4. Compile the test project

$ g++ -o main libtest.so main.cc

5. Run the test project

$ ./main
1 + 3 = 4
1 * 3 = 3