diff -r 000000000000 -r e4d67989cc36 ossrv_pub/boost_apis/boost/lambda/detail/lambda_traits.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ossrv_pub/boost_apis/boost/lambda/detail/lambda_traits.hpp Tue Feb 02 02:01:42 2010 +0200 @@ -0,0 +1,527 @@ +// - lambda_traits.hpp --- Boost Lambda Library ---------------------------- +// +// Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi) +// +// Distributed under the Boost Software License, Version 1.0. (See +// accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) +// +// For more information, see www.boost.org +// ------------------------------------------------------------------------- + +#ifndef BOOST_LAMBDA_LAMBDA_TRAITS_HPP +#define BOOST_LAMBDA_LAMBDA_TRAITS_HPP + +#include "boost/type_traits/transform_traits.hpp" +#include "boost/type_traits/cv_traits.hpp" +#include "boost/type_traits/function_traits.hpp" +#include "boost/type_traits/object_traits.hpp" + +namespace boost { +namespace lambda { + +// -- if construct ------------------------------------------------ +// Proposed by Krzysztof Czarnecki and Ulrich Eisenecker + +namespace detail { + +template struct IF { typedef Then RET; }; + +template struct IF { + typedef Else RET; +}; + + +// An if construct that doesn't instantiate the non-matching template: + +// Called as: +// IF_type::type +// The matching template must define the typeded 'type' +// I.e. A::type if condition is true, B::type if condition is false +// Idea from Vesa Karvonen (from C&E as well I guess) +template +struct IF_type_ +{ + typedef typename T::type type; +}; + + +template +struct IF_type +{ + typedef typename + IF_type_::RET >::type type; +}; + +// helper that can be used to give typedef T to some type +template struct identity_mapping { typedef T type; }; + +// An if construct for finding an integral constant 'value' +// Does not instantiate the non-matching branch +// Called as IF_value::value +// If condition is true A::value must be defined, otherwise B::value + +template +struct IF_value_ +{ + BOOST_STATIC_CONSTANT(int, value = T::value); +}; + + +template +struct IF_value +{ + BOOST_STATIC_CONSTANT(int, value = (IF_value_::RET>::value)); +}; + + +// -------------------------------------------------------------- + +// removes reference from other than function types: +template class remove_reference_if_valid +{ + + typedef typename boost::remove_reference::type plainT; +public: + typedef typename IF< + boost::is_function::value, + T, + plainT + >::RET type; + +}; + + +template struct remove_reference_and_cv { + typedef typename boost::remove_cv< + typename boost::remove_reference::type + >::type type; +}; + + + +// returns a reference to the element of tuple T +template struct tuple_element_as_reference { + typedef typename + boost::tuples::access_traits< + typename boost::tuples::element::type + >::non_const_type type; +}; + +// returns the cv and reverence stripped type of a tuple element +template struct tuple_element_stripped { + typedef typename + remove_reference_and_cv< + typename boost::tuples::element::type + >::type type; +}; + +// is_lambda_functor ------------------------------------------------- + +template struct is_lambda_functor_ { + BOOST_STATIC_CONSTANT(bool, value = false); +}; + +template struct is_lambda_functor_ > { + BOOST_STATIC_CONSTANT(bool, value = true); +}; + +} // end detail + + +template struct is_lambda_functor { + BOOST_STATIC_CONSTANT(bool, + value = + detail::is_lambda_functor_< + typename detail::remove_reference_and_cv::type + >::value); +}; + + +namespace detail { + +// -- parameter_traits_ --------------------------------------------- + +// An internal parameter type traits class that respects +// the reference_wrapper class. + +// The conversions performed are: +// references -> compile_time_error +// T1 -> T2, +// reference_wrapper -> T& +// const array -> ref to const array +// array -> ref to array +// function -> ref to function + +// ------------------------------------------------------------------------ + +template +struct parameter_traits_ { + typedef T2 type; +}; + +// Do not instantiate with reference types +template struct parameter_traits_ { + typedef typename + generate_error:: + parameter_traits_class_instantiated_with_reference_type type; +}; + +// Arrays can't be stored as plain types; convert them to references +template struct parameter_traits_ { + typedef T (&type)[n]; +}; + +template +struct parameter_traits_ { + typedef const T (&type)[n]; +}; + +template +struct parameter_traits_ { + typedef volatile T (&type)[n]; +}; +template +struct parameter_traits_ { + typedef const volatile T (&type)[n]; +}; + + +template +struct parameter_traits_, Any >{ + typedef T& type; +}; + +template +struct parameter_traits_, Any >{ + typedef T& type; +}; + +template +struct parameter_traits_, Any >{ + typedef T& type; +}; + +template +struct parameter_traits_, Any >{ + typedef T& type; +}; + +template +struct parameter_traits_ { + typedef void type; +}; + +template +struct parameter_traits_, Any > { + typedef lambda_functor type; +}; + +template +struct parameter_traits_, Any > { + typedef lambda_functor type; +}; + +// Are the volatile versions needed? +template +struct parameter_traits_, Any > { + typedef lambda_functor type; +}; + +template +struct parameter_traits_, Any > { + typedef lambda_functor type; +}; + +} // end namespace detail + + +// ------------------------------------------------------------------------ +// traits classes for lambda expressions (bind functions, operators ...) + +// must be instantiated with non-reference types + +// The default is const plain type ------------------------- +// const T -> const T, +// T -> const T, +// references -> compile_time_error +// reference_wrapper -> T& +// array -> const ref array +template +struct const_copy_argument { + typedef typename + detail::parameter_traits_< + T, + typename detail::IF::value, T&, const T>::RET + >::type type; +}; + +// T may be a function type. Without the IF test, const would be added +// to a function type, which is illegal. + +// all arrays are converted to const. +// This traits template is used for 'const T&' parameter passing +// and thus the knowledge of the potential +// non-constness of an actual argument is lost. +template struct const_copy_argument { + typedef const T (&type)[n]; +}; +template struct const_copy_argument { + typedef const volatile T (&type)[n]; +}; + +template +struct const_copy_argument {}; +// do not instantiate with references + // typedef typename detail::generate_error::references_not_allowed type; + + +template<> +struct const_copy_argument { + typedef void type; +}; + + +// Does the same as const_copy_argument, but passes references through as such +template +struct bound_argument_conversion { + typedef typename const_copy_argument::type type; +}; + +template +struct bound_argument_conversion { + typedef T& type; +}; + +// The default is non-const reference ------------------------- +// const T -> const T&, +// T -> T&, +// references -> compile_time_error +// reference_wrapper -> T& +template +struct reference_argument { + typedef typename detail::parameter_traits_::type type; +}; + +template +struct reference_argument { + typedef typename detail::generate_error::references_not_allowed type; +}; + +template +struct reference_argument > { + typedef lambda_functor type; +}; + +template +struct reference_argument > { + typedef lambda_functor type; +}; + +// Are the volatile versions needed? +template +struct reference_argument > { + typedef lambda_functor type; +}; + +template +struct reference_argument > { + typedef lambda_functor type; +}; + +template<> +struct reference_argument { + typedef void type; +}; + +namespace detail { + +// Array to pointer conversion +template +struct array_to_pointer { + typedef T type; +}; + +template +struct array_to_pointer { + typedef const T* type; +}; +template +struct array_to_pointer { + typedef T* type; +}; + +template +struct array_to_pointer { + typedef const T* type; +}; +template +struct array_to_pointer { + typedef T* type; +}; + + +// --------------------------------------------------------------------------- +// The call_traits for bind +// Respects the reference_wrapper class. + +// These templates are used outside of bind functions as well. +// the bind_tuple_mapper provides a shorter notation for default +// bound argument storing semantics, if all arguments are treated +// uniformly. + +// from template foo(const T& t) : bind_traits::type +// from template foo(T& t) : bind_traits::type + +// Conversions: +// T -> const T, +// cv T -> cv T, +// T& -> T& +// reference_wrapper -> T& +// const reference_wrapper -> T& +// array -> const ref array + +// make bound arguments const, this is a deliberate design choice, the +// purpose is to prevent side effects to bound arguments that are stored +// as copies +template +struct bind_traits { + typedef const T type; +}; + +template +struct bind_traits { + typedef T& type; +}; + +// null_types are an exception, we always want to store them as non const +// so that other templates can assume that null_type is always without const +template<> +struct bind_traits { + typedef null_type type; +}; + +// the bind_tuple_mapper, bind_type_generators may +// introduce const to null_type +template<> +struct bind_traits { + typedef null_type type; +}; + +// Arrays can't be stored as plain types; convert them to references. +// All arrays are converted to const. This is because bind takes its +// parameters as const T& and thus the knowledge of the potential +// non-constness of actual argument is lost. +template struct bind_traits { + typedef const T (&type)[n]; +}; + +template +struct bind_traits { + typedef const T (&type)[n]; +}; + +template struct bind_traits { + typedef const volatile T (&type)[n]; +}; + +template +struct bind_traits { + typedef const volatile T (&type)[n]; +}; + +template +struct bind_traits >{ + typedef T& type; +}; + +template +struct bind_traits >{ + typedef T& type; +}; + +template<> +struct bind_traits { + typedef void type; +}; + + + +template < + class T0 = null_type, class T1 = null_type, class T2 = null_type, + class T3 = null_type, class T4 = null_type, class T5 = null_type, + class T6 = null_type, class T7 = null_type, class T8 = null_type, + class T9 = null_type +> +struct bind_tuple_mapper { + typedef + tuple::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type, + typename bind_traits::type> type; +}; + +// bind_traits, except map const T& -> const T + // this is needed e.g. in currying. Const reference arguments can + // refer to temporaries, so it is not safe to store them as references. + template struct remove_const_reference { + typedef typename bind_traits::type type; + }; + + template struct remove_const_reference { + typedef const T type; + }; + + +// maps the bind argument types to the resulting lambda functor type +template < + class T0 = null_type, class T1 = null_type, class T2 = null_type, + class T3 = null_type, class T4 = null_type, class T5 = null_type, + class T6 = null_type, class T7 = null_type, class T8 = null_type, + class T9 = null_type +> +class bind_type_generator { + + typedef typename + detail::bind_tuple_mapper< + T0, T1, T2, T3, T4, T5, T6, T7, T8, T9 + >::type args_t; + + BOOST_STATIC_CONSTANT(int, nof_elems = boost::tuples::length::value); + + typedef + action< + nof_elems, + function_action + > action_type; + +public: + typedef + lambda_functor< + lambda_functor_base< + action_type, + args_t + > + > type; + +}; + + + +} // detail + +template inline const T& make_const(const T& t) { return t; } + + +} // end of namespace lambda +} // end of namespace boost + + + +#endif // BOOST_LAMBDA_TRAITS_HPP