Debugging is an essential part of software development, and one way to do it is by adding print statements to output information about the state of the program. In C, a common technique is to use a preprocessor macro to conditionally compile the print statements so that they can be easily added or removed from the code.

In this article, the author shows how to achieve this effect in Go with an example code that calculates the sum of two numbers. They demonstrate how to define a function to output debug messages and give a flag to set whether debug messages should be compiled. By using a constant declaration to control whether debug messages should be compiled, the function call can be removed altogether.

The compiler can optimize the code and remove the content of the statement. To illustrate this, the author provides a link to the repository hosting the example code.