Creating a "hello world" executable

First, we will create a simple executable from a simple hello world C++ program. The following C++ program will print out Welcome to CMake Best Practices:

#include <iostream>
int main(int, char **) {
  std::cout << "Welcome to CMake Best Practices\n";
  return 0;
}

To build this, we need to compile it and give the executable a name. Let's see what the CMakeLists.txt file to build this executable looks like:

cmake_minimum_required(VERSION 3.21)
project(
    hello_world_standalone
    VERSION 1.0
    DESCRIPTION"A simple C++ project"
    HOMEPAGE_URL https://github.com/PacktPublishing/CMake-Best-
      Practices
    LANGUAGES CXX
)
add_executable(hello_world)
target_sources(hello_world PRIVATE src/main.cpp)

With the first line, cmake_minimum_required...