Boost C++ Libraries

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Struct template vararg

boost::proto::vararg — For matching a Grammar to a variable number of sub-expressions.

Synopsis

// In header: <boost/proto/matches.hpp>

template<typename Grammar> 
struct vararg {
};

Description

An expression type proto::basic_expr<AT, proto::listN<A₀,...A_n,U₀,...U_m> > matches a grammar proto::basic_expr<BT, proto::listM<B₀,...B_n,proto::vararg<V> > > if BT is proto::_ or AT, and if A_x matches B_x for each x in [0,n] and if U_x matches V for each x in [0,m].

For example:

// Match any function call expression, regardless
// of the number of function arguments:
struct Function :
  proto::function< proto::vararg<proto::_> >
{};

When used as a transform, proto::vararg<G> applies G's transform.