Create a library without a class?

Question

I'd like to know if it's possible to create a library for Arduino that does not contain a class, just functions.

I know how to create a library with a class, but I'd like to create a library of general purpose functions that don't need to be instantiated to be used. Just used like the standard functions included in the Arduino IDE: sizeof(), etc..

Is this possible? If so, can anyone point me in the direction of a template? I've been searching, but haven't found anything.

Thanks!

Answer 1

Yes, it's possible.

Just don't make a class. Just make functions instead.

Like a class-based one, have a .cpp and a .h file. In the .cpp file (or .c file if you don't want any of the C++ functionality or 90% of the Arduino API available to you) place your functions.

In the .h file place prototypes for them. I am in the habit of adding the extern keyword, but you don't actually need to for functions.

For example:

foo.cpp:

void doSomething() {
    // whatever
}

foo.h:

extern void doSomething();

Then you can include your .h file and call your functions:

#include <foo.h>

// ...

doSomething();