How to pass an argument by reference to a C++ Interface library function?

I have the following C++ header file.

// sample header.hpp
#include <vector>

// fills in the input vector
void getData(std::vector<char>& arr) {
   char data [] = {'M', 'A', 'T', 'L', 'A', 'B', '\0'};
   arr.clear();
   for (auto c : data) {
       arr.push_back(c);
   }
}

The argument for the getData function needs to be passed by reference. How can I do that with the C++ Interface?

Answer 1

[MathWorks Support Team]

This example shows how you can pass arguments by reference with the C++ Interface.

Generate the "header-only" library definition and specify the library name as lib.

>> clibgen.generateLibraryDefinition("header.hpp","PackageName=lib" )

Build the interface and add the interface folder to the MATLAB path, where

is the full path to the lib folder.

>> build(definelib)
>> addpath('<path-to-library>\lib')

Now, you can use the library and pass by reference in the following way.

>> arr = clib.array.lib.Char(1); % array of size 1
>> clib.lib.getData(carr); % fill in carr by calling the function
>> char(carr.int8) % convert data into MATLAB