Function template keep

boost::xpressive::keep — Create an independent sub-expression.

Synopsis

// In header: <boost/xpressive/regex_primitives.hpp>


template<typename Expr> unspecified keep(Expr const & expr);

Description

Turn off back-tracking for a sub-expression. Any branches or repeats within the sub-expression will match only one way, and no other alternatives are tried.

	Note
	keep(expr) is equivalent to the perl (?>...) extension.

Parameters:

expr

The sub-expression to modify.