Macro Templates, by example.

Posted by on July 13, 2009

Heres an example of what I call “macro templates” in PureBasic. A template encapsulates certain functionality, allowing you to dynamically generate the code in a flexible manner.

This example implements a bare-bones n-vector library using a structure and a static array:

It might look strange/complicated at first, but once you read it you’ll realize it’s fairly simple.

Let’s see the usage of this particular template:

Cool, huh?. And you can define any amount of elements with any basic type.

Of course we sacrificed speed for flexibility. In those cases where we have to define n-vectors, this would be an ideal solution. For everything else, I suggest a specific library, such as my vec3 macro lib.

Using this principle you can abstract almost anything, within reason. One good example is my object factory template. ┬áIdeally one would have arrays, lists, etc. Implemented in this very same way, in such case the possibilities would be endless and you’d be able to define dynamic lists/arrays inside structures, etc.

I strongly advice you to implement at least one of those templates, even if it’s just for an exercise.

Having the extra tools can’t hurt!