lst-0001-book.cpp
// https://godbolt.org/z/j6WWxPheP
// Filename: my-macros.hpp
#ifndef MY_MACROS_HPP // Include Guard
#define MY_MACROS_HPP
#include <iostream> // cout, cerr
#include <vector>
#ifdef OUTPUT_TO_STANDARD
# define OUT std::cout
#else
# define OUT std::cerr
#endif
#define MESSAGE(text) { (OUT) << text << "\n"; }
using container_type = std::vector<int>;
static constexpr unsigned SIZE = 10;
#endif