Function 'version' not supported for code generation (R2021a)

For various reasons, I want my generated code to know which version of MATLAB codegen generated the code, because coder prior to R2023a would take a matlab function:

function [ a, b ] = foo ( c, d ) …

and generate it to

void foo( TypeC c, TypeDd, TypeA* a, TypeB* b);

but after R2023a, it would generate the function as:

TypeA foo( TypeC c, TypeD d, TypeB& b);

So it became necessary, in order to call functions generated a particular version of Matlab, I needed to know which version of coder generated the library, so I wrote a simple function that I asked coder to generate for me:

function [ n ] = mversion()
    v = extractBefore( version, ' ' );
    a = str2double(extractBefore( v, '.' )) * 1e9;     vb = extractAfter( v, '.');
    b = str2double(extractBefore( vb, '.' )) * 1e6;
    n = (a + b)/1e9;
end

This code generates into a C++ function perfectly fine in many versions of Matlab coder from R2021a through R2023a, except in a recent installation of Matlab R2021a (older version of Matlab necessary to match a customer's environment), I get the error

??? Function 'version' not supported for code generation

What would cause this to successfully generate in one installation of Matlab 2021a and not another?

[Walter Roberson]

Can you use verLessThan ?

[Ivans Chou]

So, I tried:

if coder.const( verLessThan( 'matlab', '9.14' ))
    % old way ... 
else
    % after R2023a way ...
end

and I get

??? Function 'verLessThan' not supported for code generation.

Something specifically unhappy about my coder installation. Did I forget to configure something in coder after I installed the toolbox?

[Ivans Chou]

Just as a sanity check, I ran the Coder Toolbox "Euclidean" example in my R2021a installation and it generated successfully, so it's installed correctly.

[Walter Roberson]

By the way: R2020b introduced isMATLABReleaseOlderThan and matlabRelease . But it looks like code generation is not available for those either.

Answer 1

[Richard McCormack]

Hi Ivans,

It looks like MATLAB Coder support for version was officially introduced in R2021b.

If you need to use version in R2021a, I recommend using the following:

myversion = coder.const(@feval, 'version');

This should work in R2021a as well as current releases.

Let me know if that works for you.

Best,

Richard

[Ivans Chou]

Yes. Works in R2021a. I will check on later versions, I think this is the solution.

[Richard McCormack]

Glad to hear it :)