How to use mexPrintf with C++ MEX Functions

Hi there

I am testing the new C++ MEX API with Matlab 2018b. However, when try to use mexPrintf, I found that it is only defined in mex.h but not mex.hpp. Include mex.hpp and mex.h in the same time is not allowed in mex function. Is there any other ways to use mexPrinft or print out something in matlab command windows if C++ MEX API is used?

A simple example for testing is attached below. If #include <mex.h> is uncommented, compilation will fail.

#include <mex.hpp>
#include <mexAdapter.hpp>
//#include <mex.h>

using namespace matlab::data;
using matlab::mex::ArgumentList;

class MexFunction : public matlab::mex::Function
{
public:
    void operator()(ArgumentList outputs, ArgumentList inputs)
    {
        const double offSet = inputs[0][0];
        TypedArray<double> doubleArray = std::move(inputs[1]);
        for (auto& elem : doubleArray)
        {
            elem += 1*offSet;
        }
        outputs[0] = doubleArray;
        //mexPrintf("Hello");
    }
};

Answer 1

[Steven Lord]

Take a look at this documentation page for one potential technique.

[wh z]

It works! Thanks~

[Tucker Downs]

This is a terrible solution. It shouldn't take so much code (from our, the users, side) to run disp "hello world" from mex. Why isn't there a convienience function in the C++ api?

[Cris Luengo]

This is indeed ridiculous. The C++ API could very easily define an output stream that is connected to the MATLAB console, something like matlab::engine::cout.

[Jonathan]

Still not fixed yet. Put in ticket request:

"Thank you for using our products and providing helpful feedback. An enhancement request has been submitted and we will let you know when we finalize the update."