how to use `utility/` folder in library development

[RodrigoDornelles]

I can't find clear documentation, I would like to put optional extras in my lib in addition to the main core.

• structfolder

src/
  foo/
    foo.c
    foo.h
   libname.h
   libname.c
utility/
   libnameComplement.h
   libnameComplement.h

how to include libnameComplement ?

I'm using this link to guide me, but I'm not able to resolve the headers.
https://arduino.github.io/arduino-cli/0.33/library-specification/

#include <libname.h> // works
#include <libnameComplement.h> // not works

void setup()
{
  libnamee_func();
  libnameComplement_func();
{

void loop()
{

}

[per1234]

Hi @RodrigoDornelles. The key is this statement in the Arduino Library Specification:

https://arduino.github.io/arduino-cli/0.33/library-specification/#source-code

For backward compatibility with Arduino IDE 1.0.x, the library author may opt to place source code into the root folder, instead of the folder called src. In this case the 1.0 library format is applied and the source code is searched from the library root folder and the utility folder

Note the "instead". You must not use both src and utility folders in the library. It is an either/or thing.

If you use the "1.5" library format, the contents of the src subfolder are compiled recursively. So you are welcome to organize the code files into subfolders of the src folder. So you can separate these "optional extras" into a subfolder of the src folder if you like. You can even name that folder utility if you like.

I'll provide an example of a valid library structure:

libname/
├── library.properties
└── src/
    ├── foo/
    │   ├── foo.c
    │   └── foo.h
    ├── libname.cpp
    ├── libname.h
    └── libnameComplement/
        └── libnameComplement.h

how to include libnameComplement?

The library users can use the following #include directives in their code:

#include <libname.h>  // A file from the root source folder must be #included first to cause the library to be added to the compiler search path.
#include <libnameComplement/libnameComplement.h>  // The path is relative to the root source folder

[RodrigoDornelles]

@per1234 I was looking for something that doesn't always compile, as it ends up facing conflicts in my project in the way the Arduino IDE/CLI works.

libname/
├── library.properties
└── src/
    ├── foo/
    │   ├── foo.c
    │   └── foo.h
    ├── libname.cpp
    ├── libname.h
    └── libnameComplement/
        └── libnameComplement.h
    └── libnameComplement2/
        └── libnameComplement2.h

let's suppose that libnameComplement and libnameComplement2 have a function of the same name called samefunc() and I want to give the availability of using libname to use this samefunc() according to what was chosen by the user of the IDE.

Temporary solution

currently I made some not very elegant solutions, which fail to compile this function with the library, to make it compile with sketch and be properly linked.

#include <libname.h>
#include <libnameComplement/libnameComplement.c>  //nasty solution for including a .c file