pcre正则相关记录

Character Classes that are Always Supported

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

原文链接：Character Classes that are Always Supported - 1.49.0

Name	POSIX-standard name	Description
alnum	Yes	Any alpha-numeric character.
alpha	Yes	Any alphabetic character.
blank	Yes	Any whitespace character that is not a line separator.
cntrl	Yes	Any control character.
d	No	Any decimal digit
digit	Yes	Any decimal digit.
graph	Yes	Any graphical character.
l	No	Any lower case character.
lower	Yes	Any lower case character.
print	Yes	Any printable character.
punct	Yes	Any punctuation character.
s	No	Any whitespace character.
space	Yes	Any whitespace character.
unicode	No	Any extended character whose code point is above 255 in value.
u	No	Any upper case character.
upper	Yes	Any upper case character.
w	No	Any word character (alphanumeric characters plus the underscore).
word	No	Any word character (alphanumeric characters plus the underscore).
xdigit	Yes	Any hexadecimal digit character.