But, note that the topic title will already appear in the meta description, so it won't be necessarily a great SEO enhancement to repeat them this way.
Well as i know you need to have the meta keywords separated by coma or space or coma and space. In titles you have something like this: "->title1 seo improvements for today<-" so you have metas like this:
<meta keywords="->title1 seo improvements for today<-,key1,key2,key3,key4,key5,key6...">
As you can see the meta keywords are not the same, i mean title does not have the comas in it, also you would need to change all to spaces and not comas to have the title words as keywords. And for titles the characters like "->,::,---" are not good for meta keywords, and you will have those in many titles like "problem - error in functions.php" so the metakeyword title is "problem -
error in functions.
php", characters are not replaced and thats bad for metakeywords as i know.
But also putting full text without stating spaces as limit for keywords is bad, and you have mixed spaces and comas tant the same time, thats not possible.
But i know that from meta keywords guideline from 2004, maybe you know other things for this.
Even i strongly recommend to have the title words in the meta keywords, and a function to depure the title words to be with coma and to eliminate characters that are not part from the word.