You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: regexptokens.m
    path of file: ./repos/Image-Harmonization-Dataset-iHarmony4/Lalonde and Efros/utils/3rd_party/multicore
    
    the code of the file until where you have to start completion: function varargout = regexptokens(str, expr)
%REGEXPTOKENS  Get tokens using regular expressions.
%		[TOKEN1, TOKEN2, ...] = REGEXPTOKENS(STRING, EXPRESSION) returns the
%		tokens returned by function REGEXP in a cell array. 
%

    
function varargout = regexptokens(str, expr)
%REGEXPTOKENS  Get tokens using regular expressions.
%		[TOKEN1, TOKEN2, ...] = REGEXPTOKENS(STRING, EXPRESSION) returns the
%		tokens returned by function REGEXP in a cell array. 
%
%		Example:
%		fileNr = regexptokens('radarsim3_19_rdd.mat', 'radarsim3_(\d+)')
%
%		Markus Buehren
%
%		See also REGEXP.

[s,f,t] = regexp(str, expr, 'once'); %#ok

argout = cell(nargout, 1);
if isempty(t)
	varargout = argout;
	return
else
	for n=1:nargout
		
		% for compatibility to Matlab 7.2
		if isnumeric(t)
			t = {t}; %#ok
		end