...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::proto::call — Make the given CallableTransform into a PrimitiveTransform.
// In header: <boost/proto/transform/call.hpp>
template<typename T>
struct call : proto::transform< call<T> > {
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data> {
// types
typedef see-below
result_type;
// public member functions
result_type operator()(typename impl::expr_param,
typename impl::state_param,
typename impl::data_param) const;
};
};
The purpose of proto::call<>
is to annotate a transform as callable
so that proto::when<>
knows
how to apply it. The template parameter must be either a PrimitiveTransform or a
CallableTransform; that is, a function type for which the return type is a callable
PolymorphicFunctionObject.
For the complete description of the behavior of the proto::call<>
transform, see the documentation for the nested
proto::call::impl<>
class template.