document Mex required/optional

Author: scivision

+stdlib/create_symlink.m

@@ -31,6 +31,8 @@
     % see example/Filesystem.java for this working in plain Java.
     % see example/javaCreateSymbolicLink.m for a non-working attempt in Matlab.
 
+    disp("use 'buildtool mex' or 'legacy_mex_build()' for faster symlink creation")
+
     if ispc
       cmd = "pwsh -c " + '"' + "New-Item -ItemType SymbolicLink -Path " + link + ...
             " -Target " + target + '"';

+stdlib/is_char_device.m

@@ -1,4 +1,4 @@
-%% IS_CHAR_DEVICE is path a character device
+%% IS_CHAR_DEVICE is path a character device (Matlab requires MEX)
 % e.g. NUL, /dev/null
 % false if file does not exist
 

+stdlib/is_rosetta.m

@@ -1,5 +1,5 @@
-%% IS_ROSETTA is running on Apple Silicon using Rosetta
-% this would be true if Matlab is build for Intel x86_64
+%% IS_ROSETTA on Apple Silicon via Rosetta (Matlab optional MEX)
+% true if Matlab on Apple Silicon CPU is built for Intel x86_64
 
 function r = is_rosetta()
 r = false;

+stdlib/set_permissions.m

@@ -0,0 +1,11 @@
+%% SET_PERMISSIONS set path permissions (Matlab requires MEX)
+%
+%%% Inputs
+% * path (1,1) string
+% * readable (1,1) int (-1 remove read permission, 0 no change, 1 add read permission)
+% * writable (1,1) int (-1 remove write permission, 0 no change, 1 add write permission)
+% * executable (1,1) int (-1 remove execute permission, 0 no change, 1 add execute permission)
+%%% Outputs
+% * ok (1,1) logical
+%
+% This function is written in C++ using STL <filesystem> and is only available in Matlab.

+stdlib/windows_shortname.m

@@ -1,4 +1,5 @@
-%% WINDOWS_SHORTNAME Retrieves the Windows short name (8.3 character) form
+%% WINDOWS_SHORTNAME Retrieves the Windows short name (Matlab optional MEX)
+% (8.3 character) filename
 %
 %  Example of using a COM server (Scripting.FileSystemObject) in Windows
 %