Boost C++ Libraries Home Libraries People FAQ More

PrevUpHomeNext

Function template optional

boost::xpressive::optional — Make a sub-expression optional. Equivalent to !as_xpr(expr).

Synopsis

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


template<typename Expr> 
   
  ( expr);

Description

Parameters:

expr

The sub-expression to make optional.


PrevUpHomeNext