I wanted to share a trick I learned a while back, that is pretty useful. Personally, I’m not a fan of including code in your executable/bytecode that is never used, because it has the risk of exposing additional implementation, and generally makes for larger DLLs/Jars. One nice thing I can say about C# is that they did not completely remove the idea of conditional compilation. In C#, you can do the following:
#define LETS_DANCE
...
#if LETS_DANCE
// ... do something ...
#endif
However, C#’s conditional compilation is completely restricted to only being able to define a boolean, where the existence of the preprocessor symbol means it exists, and otherwise, it doesn’t. Makes sense. Conditional compilation without all the nasty misuses of them you see in C++ programs. Seems to be the best of both worlds and an obvious leg up on Java, right?
Well, actually not really. Turns out that Java has supported something similar since day one, also. In Java, the equivalent is this:
public static final LETS_DANCE = false;
...
if (LETS_DANCE)
{
// ... do something ...
}
#endif
Why is this guaranteed to work and not include the unreachable code? Turns out there is an important note in Java. Java will not output code that is obviously unreachable. To be obviously unreachable it needs to be known at compile time as a static final constant variable. So, there you go. Definitely a useful thing.
