simulink-use-c-function-block

Add a C Function block, point it to your headers and sources via custom code settings, then configure symbols with the SymbolSpec API. C++ classes are declared as Persistent symbols with Type 'Class: ClassName' and methods are called directly in code sections.

Get the block's SymbolSpec object with get_param, then use addSymbol and set each symbol's Scope, Type, and Size properties. Output sizes can use size() expressions derived from inputs, while input sizes may be inherited with '-1'.

Yes. Declare the class instance as a Persistent scope symbol with Type 'Class: ClassName', with constructor arguments in the Name property. The class must be defined in an external header, and constructor arguments must be Parameter or Constant symbols.

Block-level custom code via CustomCodeSettingLocation 'BlockSettings' was introduced in R2024a. On R2023a and R2023b, only model-level configuration through ModelConfigurationParameters is available.

Code sections like OutputCode and StartCode do not accept #include directives. Headers must be specified through custom code settings such as SimCustomHeaderFile on the block or SimCustomHeaderCode at the model level.

Avoid it for MATLAB Function block logic, which uses MATLAB syntax rather than C/C++, and for code generation workflows targeting Embedded Coder. This approach covers simulation-time configuration of C/C++ integration only.