Struct template child

boost::proto::functional::child — A callable PolymorphicFunctionObject that is equivalent to the proto::child() function.

Synopsis

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

template<typename N = mpl::long_<0> > 
struct child :  proto::callable {
  // member classes/structs/unions
  template<typename This, typename Expr> 
  struct result<This(Expr)> :  proto::result_of::child< Expr, N > {
  };

  // public member functions
  template<typename Expr> 
    typename proto::result_of::child< Expr &, N >::type 
    operator()(Expr &) const;
  template<typename Expr> 
    typename proto::result_of::child< Expr const &, N >::type 
    operator()(Expr const &) const;
};

Description

A callable PolymorphicFunctionObject that is equivalent to the proto::child() function. N is required to be an MPL Integral Constant.

`child` public member functions

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

Return the N^th child of the given expression.

Parameters:

expr

The expression node.

Requires:

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

N::value < Expr::proto_arity::value

Returns:

proto::child<N>(expr)

Throws:

Will not throw.

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

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Struct template child

Synopsis

Description

child public member functions

`child` public member functions