32 Regular expressions library [re]

32.6 Class template regex_traits [re.traits]

Table 140: Character class names and corresponding ctype masks [tab:re.traits.classnames]
Narrow character name
Wide character name
Corresponding ctype_base​::​mask value
"alnum"
L"alnum"
ctype_base​::​alnum
"alpha"
L"alpha"
ctype_base​::​alpha
"blank"
L"blank"
ctype_base​::​blank
"cntrl"
L"cntrl"
ctype_base​::​cntrl
"digit"
L"digit"
ctype_base​::​digit
"d"
L"d"
ctype_base​::​digit
"graph"
L"graph"
ctype_base​::​graph
"lower"
L"lower"
ctype_base​::​lower
"print"
L"print"
ctype_base​::​print
"punct"
L"punct"
ctype_base​::​punct
"space"
L"space"
ctype_base​::​space
"s"
L"s"
ctype_base​::​space
"upper"
L"upper"
ctype_base​::​upper
"w"
L"w"
ctype_base​::​alnum
"xdigit"
L"xdigit"
ctype_base​::​xdigit