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Struct template impl

boost::proto::when<Grammar, R(A...)>::impl

Synopsis

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


template<typename Expr, typename State, typename Data> 
struct impl :  proto::transform_impl< Expr, State, Data > {
  // types
  typedef proto::call<                                       ;        // For exposition only
  typedef proto::make<                                       ;        // For exposition only
  typedef proto::is_callable< ;        // For exposition only
  typedef   ;

  // public member functions
   (, 
                         , 
                         ) ;
};

Description

impl public member functions

  1.  ( expr, 
                            state, 
                            data) ;

    Evaluate R(A...) as a transform either with proto::call<> or with proto::make<> depending on whether proto::is_callable<R>::value is true or false.

    Parameters:

    data

    An arbitrary data

    expr

    The current expression

    state

    The current state

    Requires:

    proto::matches<Expr, Grammar>::value is true.

    Returns:

    which()(expr, state, data)


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