Thanks for all the feedback. You are all correct. My users are inputting a string to be split like a shell. Yet, there is a complication since the user's input would also like CPP pre-processing which will not modify things within quotes. For this reason, I would like to provide the users a method for quoting without quotes (e.g. qq{} or q{}). These operators would allow CPP to perform substitutions which is great. Yet, afterwards, I would continue to want to "parse" the input string like a shell using something like "quotewords".