...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::xpressive::after — Look-behind assertion.
// In header: <boost/xpressive/regex_primitives.hpp> template<typename Expr> unspecified after(Expr const & expr);
after(expr) succeeds if the expr sub-expression would match at the current position minus N in the sequence, where N is the width of expr. expr is not included in the match. For instance, after("foo") succeeds if we are after a "foo". Look-behind assertions can be negated with the bit-complement operator.
Note | |
---|---|
after(expr) is equivalent to the perl (?<=...) extension. ~after(expr) is a negative look-behind assertion, equivalent to the perl (?<!...) extension. |
Parameters: |
|
||
Requires: |
expr cannot match a variable number of characters. |