Arguments block syntax not being recognised

I'm trying to use an arguments block for input argument validation in a standalone function. I followed the instructions here, and even tried copying the forwardSpeed example:

function forwardSpeed(a,b,c)
    arguments
        a double
        b char
        c SpeedEnum
    end

    % Function code
    disp(class(a)) % Line 9 (where the error is located)
    disp(class(b))
    disp(class(c))
end

however the editor does not highlight the syntax properly, and when I try to run it, I get the following error:

>>forwardSpeed(1,'a',2)
Error: File: /home/$USER/forwardSpeed.m Line: 9 Column: 5
This statement is not inside any function.
 (It follows the END that terminates the definition of the function "forwardSpeed".)
 

The output for my MATLAB version:

>>version

ans =

    '9.6.0.1214997 (R2019a) Update 6'

Answer 1

[Adam]

This was only introduced in 2019b (you can see at the bottom of the help page for 'arguments'). It is one of the disadvantages of using the online help (which is always for the latest version) rather than your offline help (which is for your version).

You can use

doc validateattributes

to achieve similar though, which is what I have been doing the past many years.

[Will Hardiman]

Oof. I checked for that on the bottom of the page I linked, but not on arguments! Thanks for the suggestion

[Neon Argentus]

I have the 2020a version and very interestingly I also have the exact same problem. The word "argument" doesn't turn blue.

[Neon Argentus]

I found the problem.

Before the arguments statement, there should be no codeword. Otherwise it works.