C++ code importer cannot find the cmath library

Hi, I'm trying to import some C++ controller code I have written to test it with my simulink plant before putting it on hardware. I'm following this tutorial:

https://au.mathworks.com/help/releases/R2025b/simulink/ug/import-custom-code-using-the-simulink-code-importer-wizard.html?searchHighlight=Code+Importer+wizard&s_tid=doc_srchtitle

When I get to the "Analyze" stage it throws this error:

Error:Failed to parse custom code.

Caused by:

"/Users/alfieeagleton/Desktop/Uni/Thesis/Matlab/cpp/include/actuator.hpp", line 23: error: cannot open source file "cmath"

| #include

| ^

I have included <cmath> and <algorithm> and it will throw an error on both if I remove <cmath>.

Does anyone know what I'm doing wrong?

Thanks

Answer 1

[Adarsh]

Hi @Alfred,

As per my understanding you are encountering an error when using the Simulink Code Importer Wizard to import your C++ controller code. The error message indicates that the parser cannot find the standard C++ library header "cmath" (and "algorithm" if you remove "cmath").

This issue typically occurs when MATLAB does not have the correct compiler configuration for locating C++ standard library headers on macOS.

You can try running the following command in MATLAB to configure your C++ compiler to fix the issue:

mex -setup C++

After running this command, try using the Code Importer Wizard again. This should allow MATLAB to locate the standard library headers automatically.

If the issue persists after running "mex -setup C++", you can manually specify the include paths using a configuration object as show in below example:

cfg = coder.config('lib'); 
cfg.CustomInclude = {'/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1', '/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include'};

The "CustomInclude" property tells MATLAB where to find the C++ standard library headers.

Alternatively, you can manually add the standard header files to code importer similar to the procedure done in the below MATLAB Answer post:

https://www.mathworks.com/matlabcentral/answers/1849288-how-to-include-a-directory-along-with-subfolders-in-a-including-path-of-code-importer-wizard

I hope this helps!