Boost-Supported RegEx Character Classes

The following character class names are always supported by Boost.Regex:

Name POSIX-standard name Description Example
[: alnum :] Yes Alpha-numeric characters [A-Za-z0-9]
[:alpha:] Yes Alphabetic characters [A-Za-z]
[: blank:] Yes Whitespace characters that are not line separators space or tab
[: cntrl:] Yes Control characters Any character not part of the character classes: [:upper:], [:lower:], [:alpha:], [:digit:], [:punct:], [:graph:], [:print:], [:xdigit:]
[: d:] No Decimal digits [0-9]
[:digit:] Yes Decimal digits [0-9]
[:graph:] Yes Characters with graphic representations [A-Z][a-z][0-9][:punct:]
[: l:] No Lower case characters [a-z]
[: lower:] Yes Lower case characters [a-z]
[: print:] Yes Characters that display when printed [:graph:] and space
[:punct:] Yes Punctuation characters ! ' # S % & ' ( ) * + , - . / : ; < = > ? @ [ / ] ^ _ { | } ~
[:s:] No Whitespace characters tab, new line, vertical tab, form feed, carriage return, space
[:space:] Yes Whitespace characters tab, new line, vertical tab, form feed, carriage return, space
[:unicode:] No Extended characters whose code point value is above 255 UnicodeĀ® character specific information
[:u:] No Upper case characters [A-Z]
[:upper:] Yes Upper case characters [A-Z]
[:w:] No Alphanumeric characters and underscore [A-Za-z0-9_]
[: word:] No Alphanumeric characters and underscore [A-Za-z0-9_]
[:xdigit:] Yes Hexadecimal digit characters [A-Fa-f0-9]