Function child

Function child_c

boost::proto::child_c — Return the N^th child of the specified Proto expression.

Synopsis

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


template<long N, typename Expr> 
  typename proto::result_of::child_c< Expr &, N >::type child_c(Expr & expr);
template<long N, typename Expr> 
  typename proto::result_of::child_c< Expr const &, N >::type 
  child_c(Expr const & expr);

Description

Return the N^th child of the specified Proto expression. The child is returned by reference.

Requires:

proto::is_expr<Expr>::value is true.

N < Expr::proto_arity::value

Returns:

A reference to the N^th child of expr.

Throws: Will not throw.