Boost C++ Libraries Home Libraries People FAQ More

PrevUpHomeNext

Struct template impl

boost::proto::_env_var::impl

Synopsis

// In header: <boost/proto/transform/env.hpp>



struct impl :  proto::transform_impl<Expr, State, Data> > {
  // types
  typedef typename proto::result_of::env_var<Data, Key>::type result_type;

  // public member functions
  result_type operator()(typename impl::expr_param, 
                         typename impl::state_param, 
                         typename impl::data_param) const;
};

Description

impl public member functions

  1. result_type operator()(typename impl::expr_param, typename impl::state_param, 
                           typename impl::data_param data) const;

    Fetches the value associated with Key from the transform environment passed in the data (third) parameter.

    Parameters:

    data

    The current transform environment

    Requires:

    proto::is_env<Data>::value is true.

    Returns:

    proto::env_var(data)


PrevUpHomeNext