If the code and the comments disagree, then both are probably wrong.
– Norm Schryer
In <regex>, the standard library provides support for regular expressions:
• regex_match(): Match a regular expression against a string (of known size).
• regex_search(): Search for a string that matches a regular expression in an (arbitrarily long) stream of data.
• regex_replace(): Search for strings that match a regular expression in an (arbitrarily long) stream ...