How to use Simulink generate C++ code which include C++ std:: function ,for example lower_bound function

Hello guy ,I have a question , how to use simulink generate C++ Std:: function . For example, I just want lower_bound(C++ <algorithm>function) function in generation C++ code. I use matlab function , also use #include<algorithm> ，but it dosenot work,

Answer 1

[Abhiram]

Hi @ren chongling,

To use C++ standard library functions such as “lower_bound” in Simulink and use the model to generate C++ code, you will need to wrap the standard function inside a custom user-defined C++ function. A sample implementation is given:

// lower_bound_wrapper.cpp
#include <algorithm>

extern "C" int lower_bound_wrapper(const double* arr, int size, double value) {
    const double* it = std::lower_bound(arr, arr + size, value);
    return static_cast<int>(it - arr);
}

// lower_bound_wrapper.h
#ifndef LOWER_BOUND_WRAPPER_H
#define LOWER_BOUND_WRAPPER_H

#ifdef __cplusplus
extern "C" {
#endif

int lower_bound_wrapper(const double* arr, int size, double value);

#ifdef __cplusplus
}
#endif

#endif

The C++ function can be called in Simulink by using the C Caller Block (from User-Defined Functions library) and configuring the C Caller block appropriately.

The final step is to configure code generation for C++ by following the given steps:

• Go to Model Settings
• Under Code Generation > Language – set language to C++
• Under Code Generation > Custom Code:
• In Include headers – add the “lower_bound_wrapper.h” file
• In Source files – add the “lower_bound_wrapper.cpp” file
• Go to Apps > Embedded Coder (if available) or use Simulink Coder
• Click Build

Hope this helps!