regex_constants::syntax_option_type
Flags for selecting syntax options.
typedef T1 syntax_option_type;
static const syntax_option_type awk, basic, collate, ECMAScript,
egrep, extended, grep, icase, nosubs, optimize;
Remarks
The type is a bitmask type that describes language specifiers and syntax modifiers to be used when compiling a regular expression. Options can be combined with |. No more than one language specifier should be used at a time.
The language specifiers are:
basic -- compile as BRE
extended -- compile as ERE
ECMAScript -- compile as ECMAScript
awk -- compile as awk
grep -- compile as grep
egrep -- compile as egrep
The syntax modifiers are:
icase -- make matches case-insensitive
nosubs -- the implementaton need not keep track of the contents of capture groups
optimize -- the implementation should emphasize speed of matching rather than speed of regular expression compilation
collate -- make matches locale-sensitive
Requirements
Header: <regex>
Namespace: std