i think i'm to blame for the confusion, a week ago or so i added if:c and if:javascript markdown blocks to the description because C returns a struct and returns {-1,-1} in case of missing/multiple 'x's. i just edited the description again to replace the if:javascript by if-not:c now that there are more than 2 languages

I added some remarks on the translation page.

Your return type is a 1-D array containing both x and y coordinates, which is different from other translations that return a 2-D array, each containg (x,y) pairs.

Did you invent this spec?

Return an empty array if more than one x found