The Art of Global Variables in C++

This article explores effective techniques for using global variables in C++. The author argues that global variables aren't inherently bad; the key lies in their proper application. The article presents advantages and disadvantages, outlining four rules: 1. Make it hard to misuse; 2. Restore original values after changing observable states; 3. Don't return references or pointers to internal state; 4. Don't make it hard to test. Through code examples, the author demonstrates correct usage and potential pitfalls, recommending thread-local variables for multi-threading.