AMDG Attached is a patch for operators.hpp that resolves http://sourceforge.net/tracker/index.php?func=detail&aid=1602075&group_id=7586&atid=107586 <http://sourceforge.net/tracker/index.php?func=detail&aid=1602075&group_id=7586&atid=107586> and a patch for operator_return_type_traits.hpp that adds specializations for subscript_action with boost::array and plus_action with std::basic_string. It also fixes the problem of stripping off const too soon which causes errors with #include <ostream> #include <string> #include <boost/lambda/lambda.hpp> int main() { const std::string s = "hello"; std::cout << (boost::lambda::_1[4])(s) << std::endl; } In Christ, Steven Watanabe *** operators.hpp.orig Mon Dec 18 10:42:56 2006 --- operators.hpp Mon Dec 18 10:41:56 2006 *************** *** 266,274 ****

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OPER_NAME (const lambda_functor<Arg>& a, CONSTB(&b)[N]) \ { \ ! return lambda_functor< \ lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> > \ ! >(tuple<lambda_functor<Arg>, CONSTB(&)[N]>(a, b)); \ } --- 266,274 ----

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OPER_NAME (const lambda_functor<Arg>& a, CONSTB(&b)[N]) \ { \ ! return \ lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> > \ ! (tuple<lambda_functor<Arg>, CONSTB(&)[N]>(a, b)); \ } *** operator_return_type_traits.hpp.orig Mon Dec 18 10:42:30 2006 --- operator_return_type_traits.hpp Mon Dec 18 11:15:00 2006 *************** *** 1,942 **** ! // operator_return_type_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_OPERATOR_RETURN_TYPE_TRAITS_HPP ! #define BOOST_LAMBDA_OPERATOR_RETURN_TYPE_TRAITS_HPP ! ! #include "boost/lambda/detail/is_instance_of.hpp" ! #include "boost/type_traits/same_traits.hpp" ! ! #include "boost/indirect_reference.hpp" ! ! #include <cstddef> // needed for the ptrdiff_t ! #include <iosfwd> // for istream and ostream ! ! #include <iterator> // needed for operator& ! ! namespace boost { ! namespace lambda { ! namespace detail { ! ! // -- general helper templates for type deduction ------------------ ! ! // Much of the type deduction code for standard arithmetic types from Gary Powell ! ! template <class A> struct promote_code { static const int value = -1; }; ! // this means that a code is not defined for A ! ! // -- the next 5 types are needed in if_then_else_return ! // the promotion order is not important, but they must have distinct values. ! template <> struct promote_code<bool> { static const int value = 10; }; ! template <> struct promote_code<char> { static const int value = 20; }; ! template <> struct promote_code<unsigned char> { static const int value = 30; }; ! template <> struct promote_code<signed char> { static const int value = 40; }; ! template <> struct promote_code<short int> { static const int value = 50; }; ! // ---------- ! ! template <> struct promote_code<int> { static const int value = 100; }; ! template <> struct promote_code<unsigned int> { static const int value = 200; }; ! template <> struct promote_code<long> { static const int value = 300; }; ! template <> struct promote_code<unsigned long> { static const int value = 400; }; ! ! template <> struct promote_code<float> { static const int value = 500; }; ! template <> struct promote_code<double> { static const int value = 600; }; ! template <> struct promote_code<long double> { static const int value = 700; }; ! ! // TODO: wchar_t ! ! // forward delcaration of complex. ! ! } // namespace detail ! } // namespace lambda ! } // namespace boost ! ! namespace std { ! template<class T> class complex; ! } ! ! namespace boost { ! namespace lambda { ! namespace detail { ! ! template <> struct promote_code< std::complex<float> > { static const int value = 800; }; ! template <> struct promote_code< std::complex<double> > { static const int value = 900; }; ! template <> struct promote_code< std::complex<long double> > { static const int value = 1000; }; ! ! // -- int promotion ------------------------------------------- ! template <class T> struct promote_to_int { typedef T type; }; ! ! template <> struct promote_to_int<bool> { typedef int type; }; ! template <> struct promote_to_int<char> { typedef int type; }; ! template <> struct promote_to_int<unsigned char> { typedef int type; }; ! template <> struct promote_to_int<signed char> { typedef int type; }; ! template <> struct promote_to_int<short int> { typedef int type; }; ! ! // The unsigned short int promotion rule is this: ! // unsigned short int to signed int if a signed int can hold all values ! // of unsigned short int, otherwise go to unsigned int. ! template <> struct promote_to_int<unsigned short int> ! { ! typedef ! detail::IF<sizeof(int) <= sizeof(unsigned short int), ! // I had the logic reversed but ">" messes up the parsing. ! unsigned int, ! int>::RET type; ! }; ! ! ! // TODO: think, should there be default behaviour for non-standard types? ! ! } // namespace detail ! ! // ------------------------------------------ ! // Unary actions ---------------------------- ! // ------------------------------------------ ! ! template<class Act, class A> ! struct plain_return_type_1 { ! typedef detail::unspecified type; ! }; ! ! ! ! template<class Act, class A> ! struct plain_return_type_1<unary_arithmetic_action<Act>, A> { ! typedef A type; ! }; ! ! template<class Act, class A> ! struct return_type_1<unary_arithmetic_action<Act>, A> { ! typedef ! typename plain_return_type_1< ! unary_arithmetic_action<Act>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type; ! }; ! ! ! template<class A> ! struct plain_return_type_1<bitwise_action<not_action>, A> { ! typedef A type; ! }; ! ! // bitwise not, operator~() ! template<class A> struct return_type_1<bitwise_action<not_action>, A> { ! typedef ! typename plain_return_type_1< ! bitwise_action<not_action>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type; ! }; ! ! ! // prefix increment and decrement operators return ! // their argument by default as a non-const reference ! template<class Act, class A> ! struct plain_return_type_1<pre_increment_decrement_action<Act>, A> { ! typedef A& type; ! }; ! ! template<class Act, class A> ! struct return_type_1<pre_increment_decrement_action<Act>, A> { ! typedef ! typename plain_return_type_1< ! pre_increment_decrement_action<Act>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type; ! }; ! ! // post decrement just returns the same plain type. ! template<class Act, class A> ! struct plain_return_type_1<post_increment_decrement_action<Act>, A> { ! typedef A type; ! }; ! ! template<class Act, class A> ! struct return_type_1<post_increment_decrement_action<Act>, A> ! { ! typedef ! typename plain_return_type_1< ! post_increment_decrement_action<Act>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type; ! }; ! ! // logical not, operator!() ! template<class A> ! struct plain_return_type_1<logical_action<not_action>, A> { ! typedef bool type; ! }; ! ! template<class A> ! struct return_type_1<logical_action<not_action>, A> { ! typedef ! typename plain_return_type_1< ! logical_action<not_action>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type; ! }; ! ! // address of action --------------------------------------- ! ! ! template<class A> ! struct return_type_1<other_action<addressof_action>, A> { ! typedef ! typename plain_return_type_1< ! other_action<addressof_action>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type1; ! ! // If no user defined specialization for A, then return the ! // cv qualified pointer to A ! typedef typename detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::remove_reference<A>::type*, ! type1 ! >::RET type; ! }; ! ! // contentsof action ------------------------------------ ! ! // TODO: this deduction may lead to fail directly, ! // (if A has no specialization for iterator_traits and has no ! // typedef A::reference. ! // There is no easy way around this, cause there doesn't seem to be a way ! // to test whether a class is an iterator or not. ! ! // The default works with std::iterators. ! ! namespace detail { ! ! // A is a nonreference type ! template <class A> struct contentsof_type { ! typedef typename boost::indirect_reference<A>::type type; ! }; ! ! // this is since the nullary () in lambda_functor is always instantiated ! template <> struct contentsof_type<null_type> { ! typedef detail::unspecified type; ! }; ! ! ! template <class A> struct contentsof_type<const A> { ! typedef typename contentsof_type<A>::type type1; ! // return a reference to the underlying const type ! // the IF is because the A::reference in the primary template could ! // be some class type rather than a real reference, hence ! // we do not want to make it a reference here either ! typedef typename detail::IF< ! is_reference<type1>::value, ! const typename boost::remove_reference<type1>::type &, ! const type1 ! >::RET type; ! }; ! ! template <class A> struct contentsof_type<volatile A> { ! typedef typename contentsof_type<A>::type type1; ! typedef typename detail::IF< ! is_reference<type1>::value, ! volatile typename boost::remove_reference<type1>::type &, ! volatile type1 ! >::RET type; ! }; ! ! template <class A> struct contentsof_type<const volatile A> { ! typedef typename contentsof_type<A>::type type1; ! typedef typename detail::IF< ! is_reference<type1>::value, ! const volatile typename boost::remove_reference<type1>::type &, ! const volatile type1 ! >::RET type; ! }; ! ! // standard iterator traits should take care of the pointer types ! // but just to be on the safe side, we have the specializations here: ! // these work even if A is cv-qualified. ! template <class A> struct contentsof_type<A*> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* const> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* volatile> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* const volatile> { ! typedef A& type; ! }; ! ! template<class A, int N> struct contentsof_type<A[N]> { ! typedef A& type; ! }; ! template<class A, int N> struct contentsof_type<const A[N]> { ! typedef const A& type; ! }; ! template<class A, int N> struct contentsof_type<volatile A[N]> { ! typedef volatile A& type; ! }; ! template<class A, int N> struct contentsof_type<const volatile A[N]> { ! typedef const volatile A& type; ! }; ! ! ! ! ! ! } // end detail ! ! template<class A> ! struct return_type_1<other_action<contentsof_action>, A> { ! ! typedef ! typename plain_return_type_1< ! other_action<contentsof_action>, ! typename detail::remove_reference_and_cv<A>::type ! >::type type1; ! ! // If no user defined specialization for A, then return the ! // cv qualified pointer to A ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::contentsof_type< ! typename boost::remove_reference<A>::type ! >, ! detail::identity_mapping<type1> ! >::type type; ! }; ! ! ! // ------------------------------------------------------------------ ! // binary actions --------------------------------------------------- ! // ------------------------------------------------------------------ ! ! // here the default case is: no user defined versions: ! template <class Act, class A, class B> ! struct plain_return_type_2 { ! typedef detail::unspecified type; ! }; ! ! namespace detail { ! ! // error classes ! class illegal_pointer_arithmetic{}; ! ! // pointer arithmetic type deductions ---------------------- ! // value = false means that this is not a pointer arithmetic case ! // value = true means, that this can be a pointer arithmetic case, but not necessarily is ! // This means, that for user defined operators for pointer types, say for some operator+(X, *Y), ! // the deductions must be coded at an earliel level (return_type_2). ! ! template<class Act, class A, class B> ! struct pointer_arithmetic_traits { static const bool value = false; }; ! ! template<class A, class B> ! struct pointer_arithmetic_traits<plus_action, A, B> { ! ! typedef typename ! array_to_pointer<typename boost::remove_reference<A>::type>::type AP; ! typedef typename ! array_to_pointer<typename boost::remove_reference<B>::type>::type BP; ! ! static const bool is_pointer_A = boost::is_pointer<AP>::value; ! static const bool is_pointer_B = boost::is_pointer<BP>::value; ! ! static const bool value = is_pointer_A || is_pointer_B; ! ! // can't add two pointers. ! // note, that we do not check wether the other type is valid for ! // addition with a pointer. ! // the compiler will catch it in the apply function ! ! typedef typename ! detail::IF< ! is_pointer_A && is_pointer_B, ! detail::return_type_deduction_failure< ! detail::illegal_pointer_arithmetic ! >, ! typename detail::IF<is_pointer_A, AP, BP>::RET ! >::RET type; ! ! }; ! ! template<class A, class B> ! struct pointer_arithmetic_traits<minus_action, A, B> { ! typedef typename ! array_to_pointer<typename boost::remove_reference<A>::type>::type AP; ! typedef typename ! array_to_pointer<typename boost::remove_reference<B>::type>::type BP; ! ! static const bool is_pointer_A = boost::is_pointer<AP>::value; ! static const bool is_pointer_B = boost::is_pointer<BP>::value; ! ! static const bool value = is_pointer_A || is_pointer_B; ! ! static const bool same_pointer_type = ! is_pointer_A && is_pointer_B && ! boost::is_same< ! typename boost::remove_const< ! typename boost::remove_pointer< ! typename boost::remove_const<AP>::type ! >::type ! >::type, ! typename boost::remove_const< ! typename boost::remove_pointer< ! typename boost::remove_const<BP>::type ! >::type ! >::type ! >::value; ! ! // ptr - ptr has type ptrdiff_t ! // note, that we do not check if, in ptr - B, B is ! // valid for subtraction with a pointer. ! // the compiler will catch it in the apply function ! ! typedef typename ! detail::IF< ! same_pointer_type, const std::ptrdiff_t, ! typename detail::IF< ! is_pointer_A, ! AP, ! detail::return_type_deduction_failure<detail::illegal_pointer_arithmetic> ! >::RET ! >::RET type; ! }; ! ! } // namespace detail ! ! // -- arithmetic actions --------------------------------------------- ! ! namespace detail { ! ! template<bool is_pointer_arithmetic, class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1; ! ! template<class A, class B> struct return_type_2_arithmetic_phase_2; ! template<class A, class B> struct return_type_2_arithmetic_phase_3; ! ! } // namespace detail ! ! ! // drop any qualifiers from the argument types within arithmetic_action ! template<class A, class B, class Act> ! struct return_type_2<arithmetic_action<Act>, A, B> ! { ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter the whole arithmetic deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::return_type_2_arithmetic_phase_1< ! detail::pointer_arithmetic_traits<Act, A, B>::value, Act, A, B ! >, ! plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B> ! >::type type; ! }; ! ! namespace detail { ! ! // perform integral promotion, no pointer arithmetic ! template<bool is_pointer_arithmetic, class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1 ! { ! typedef typename ! return_type_2_arithmetic_phase_2< ! typename remove_reference_and_cv<A>::type, ! typename remove_reference_and_cv<B>::type ! >::type type; ! }; ! ! // pointer_arithmetic ! template<class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1<true, Act, A, B> ! { ! typedef typename ! pointer_arithmetic_traits<Act, A, B>::type type; ! }; ! ! template<class A, class B> ! struct return_type_2_arithmetic_phase_2 { ! typedef typename ! return_type_2_arithmetic_phase_3< ! typename promote_to_int<A>::type, ! typename promote_to_int<B>::type ! >::type type; ! }; ! ! // specialization for unsigned int. ! // We only have to do these two specialization because the value promotion will ! // take care of the other cases. ! // The unsigned int promotion rule is this: ! // unsigned int to long if a long can hold all values of unsigned int, ! // otherwise go to unsigned long. ! ! // struct so I don't have to type this twice. ! struct promotion_of_unsigned_int ! { ! typedef ! detail::IF<sizeof(long) <= sizeof(unsigned int), ! unsigned long, ! long>::RET type; ! }; ! ! template<> ! struct return_type_2_arithmetic_phase_2<unsigned int, long> ! { ! typedef promotion_of_unsigned_int::type type; ! }; ! template<> ! struct return_type_2_arithmetic_phase_2<long, unsigned int> ! { ! typedef promotion_of_unsigned_int::type type; ! }; ! ! ! template<class A, class B> struct return_type_2_arithmetic_phase_3 { ! enum { promote_code_A_value = promote_code<A>::value, ! promote_code_B_value = promote_code<B>::value }; // enums for KCC ! typedef typename ! detail::IF< ! promote_code_A_value == -1 || promote_code_B_value == -1, ! detail::return_type_deduction_failure<return_type_2_arithmetic_phase_3>, ! typename detail::IF< ! ((int)promote_code_A_value > (int)promote_code_B_value), ! A, ! B ! >::RET ! >::RET type; ! }; ! ! } // namespace detail ! ! // -- bitwise actions ------------------------------------------- ! // note: for integral types deuduction is similar to arithmetic actions. ! ! // drop any qualifiers from the argument types within arithmetic action ! template<class A, class B, class Act> ! struct return_type_2<bitwise_action<Act>, A, B> ! { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<Act>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! return_type_2<arithmetic_action<plus_action>, A, B>, ! plain_return_type_2<bitwise_action<Act>, plain_A, plain_B> ! >::type type; ! ! // plus_action is just a random pick, has to be a concrete instance ! ! // TODO: This check is only valid for built-in types, overloaded types might ! // accept floating point operators ! ! // bitwise operators not defined for floating point types ! // these test are not strictly needed here, since the error will be caught in ! // the apply function ! BOOST_STATIC_ASSERT(!(boost::is_float<plain_A>::value && boost::is_float<plain_B>::value)); ! ! }; ! ! namespace detail { ! ! #ifdef BOOST_NO_TEMPLATED_STREAMS ! ! template<class A, class B> ! struct leftshift_type { ! ! typedef typename detail::IF< ! boost::is_convertible< ! typename boost::remove_reference<A>::type*, ! std::ostream* ! >::value, ! std::ostream&, ! typename detail::remove_reference_and_cv<A>::type ! >::RET type; ! }; ! ! template<class A, class B> ! struct rightshift_type { ! ! typedef typename detail::IF< ! ! boost::is_convertible< ! typename boost::remove_reference<A>::type*, ! std::istream* ! >::value, ! std::istream&, ! typename detail::remove_reference_and_cv<A>::type ! >::RET type; ! }; ! ! #else ! ! template <class T> struct get_ostream_type { ! typedef std::basic_ostream<typename T::char_type, ! typename T::traits_type>& type; ! }; ! ! template <class T> struct get_istream_type { ! typedef std::basic_istream<typename T::char_type, ! typename T::traits_type>& type; ! }; ! ! template<class A, class B> ! struct leftshift_type { ! private: ! typedef typename boost::remove_reference<A>::type plainA; ! public: ! typedef typename detail::IF_type< ! is_instance_of_2<plainA, std::basic_ostream>::value, ! get_ostream_type<plainA>, //reference to the stream ! detail::remove_reference_and_cv<A> ! >::type type; ! }; ! ! template<class A, class B> ! struct rightshift_type { ! private: ! typedef typename boost::remove_reference<A>::type plainA; ! public: ! typedef typename detail::IF_type< ! is_instance_of_2<plainA, std::basic_istream>::value, ! get_istream_type<plainA>, //reference to the stream ! detail::remove_reference_and_cv<A> ! >::type type; ! }; ! ! ! #endif ! ! } // end detail ! ! // ostream ! template<class A, class B> ! struct return_type_2<bitwise_action<leftshift_action>, A, B> ! { ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::leftshift_type<A, B>, ! plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B> ! >::type type; ! }; ! ! // istream ! template<class A, class B> ! struct return_type_2<bitwise_action<rightshift_action>, A, B> ! { ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::rightshift_type<A, B>, ! plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B> ! >::type type; ! }; ! ! // -- logical actions ---------------------------------------- ! // always bool ! // NOTE: this may not be true for some weird user-defined types, ! template<class A, class B, class Act> ! struct plain_return_type_2<logical_action<Act>, A, B> { ! typedef bool type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<logical_action<Act>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<logical_action<Act>, plain_A, plain_B>::type type; ! ! }; ! ! ! // -- relational actions ---------------------------------------- ! // always bool ! // NOTE: this may not be true for some weird user-defined types, ! template<class A, class B, class Act> ! struct plain_return_type_2<relational_action<Act>, A, B> { ! typedef bool type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<relational_action<Act>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<relational_action<Act>, plain_A, plain_B>::type type; ! }; ! ! // Assingment actions ----------------------------------------------- ! // return type is the type of the first argument as reference ! ! // note that cv-qualifiers are preserved. ! // Yes, assignment operator can be const! ! ! // NOTE: this may not be true for some weird user-defined types, ! ! template<class A, class B, class Act> ! struct return_type_2<arithmetic_assignment_action<Act>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! arithmetic_assignment_action<Act>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<bitwise_assignment_action<Act>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! bitwise_assignment_action<Act>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! template<class A, class B> ! struct return_type_2<other_action<assignment_action>, A, B> { ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! other_action<assignment_action>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! // -- other actions ---------------------------------------- ! ! // comma action ---------------------------------- ! // Note: this may not be true for some weird user-defined types, ! ! // NOTE! This only tries the plain_return_type_2 layer and gives ! // detail::unspecified as default. If no such specialization is found, the ! // type rule in the spcecialization of the return_type_2_prot is used ! // to give the type of the right argument (which can be a reference too) ! // (The built in operator, can return a l- or rvalue). ! template<class A, class B> ! struct return_type_2<other_action<comma_action>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! other_action<comma_action>, plain_A, plain_B ! >::type type; ! }; ! ! // subscript action ----------------------------------------------- ! ! ! namespace detail { ! // A and B are nonreference types ! template <class A, class B> struct subscript_type { ! typedef detail::unspecified type; ! }; ! ! template <class A, class B> struct subscript_type<A*, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* const, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* volatile, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* const volatile, B> { ! typedef A& type; ! }; ! ! ! template<class A, class B, int N> struct subscript_type<A[N], B> { ! typedef A& type; ! }; ! ! // these 3 specializations are needed to make gcc <3 happy ! template<class A, class B, int N> struct subscript_type<const A[N], B> { ! typedef const A& type; ! }; ! template<class A, class B, int N> struct subscript_type<volatile A[N], B> { ! typedef volatile A& type; ! }; ! template<class A, class B, int N> struct subscript_type<const volatile A[N], B> { ! typedef const volatile A& type; ! }; ! ! } // end detail ! ! template<class A, class B> ! struct return_type_2<other_action<subscript_action>, A, B> { ! ! typedef typename detail::remove_reference_and_cv<A>::type plain_A; ! typedef typename detail::remove_reference_and_cv<B>::type plain_B; ! ! typedef typename boost::remove_reference<A>::type nonref_A; ! typedef typename boost::remove_reference<B>::type nonref_B; ! ! typedef typename ! plain_return_type_2< ! other_action<subscript_action>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::subscript_type<nonref_A, nonref_B>, ! plain_return_type_2<other_action<subscript_action>, plain_A, plain_B> ! >::type type; ! ! }; ! ! ! } // namespace lambda ! } // namespace boost ! ! ! // Forward declarations are incompatible with the libstdc++ debug mode. ! #if BOOST_WORKAROUND(__GNUC__, >= 3) && defined(_GLIBCXX_DEBUG) ! #include <string> ! #include <vector> ! #include <map> ! #include <deque> ! #else ! ! // The GCC 2.95.x uses a non-conformant deque ! #if BOOST_WORKAROUND(__GNUC__, == 2) && __GNUC_MINOR__ <= 96 ! #include <deque> ! #else ! ! namespace std { ! template <class T, class Allocator> class deque; ! } ! ! #endif ! ! namespace std { ! template <class Char, class Traits, class Allocator> class basic_string; ! template <class T, class Allocator> class vector; ! template <class Key, class T, class Cmp, class Allocator> class map; ! template <class Key, class T, class Cmp, class Allocator> class multimap; ! } ! ! #endif ! ! ! ! namespace boost { ! namespace lambda { ! ! template<class Key, class T, class Cmp, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::map<Key, T, Cmp, Allocator>, B> { ! typedef T& type; ! // T == std::map<Key, T, Cmp, Allocator>::mapped_type; ! }; ! ! template<class Key, class T, class Cmp, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::multimap<Key, T, Cmp, Allocator>, B> { ! typedef T& type; ! // T == std::map<Key, T, Cmp, Allocator>::mapped_type; ! }; ! ! // deque ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::deque<T, Allocator>, B> { ! typedef typename std::deque<T, Allocator>::reference type; ! }; ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::deque<T, Allocator>, B> { ! typedef typename std::deque<T, Allocator>::const_reference type; ! }; ! ! // vector ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::vector<T, Allocator>, B> { ! typedef typename std::vector<T, Allocator>::reference type; ! }; ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::vector<T, Allocator>, B> { ! typedef typename std::vector<T, Allocator>::const_reference type; ! }; ! ! // basic_string ! template<class Char, class Traits, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::basic_string<Char, Traits, Allocator>, B> { ! typedef typename std::basic_string<Char, Traits, Allocator>::reference type; ! }; ! template<class Char, class Traits, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::basic_string<Char, Traits, Allocator>, B> { ! typedef typename std::basic_string<Char, Traits, Allocator>::const_reference type; ! }; ! ! ! } // namespace lambda ! } // namespace boost ! ! #endif ! ! --- 1,1004 ---- ! // operator_return_type_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_OPERATOR_RETURN_TYPE_TRAITS_HPP ! #define BOOST_LAMBDA_OPERATOR_RETURN_TYPE_TRAITS_HPP ! ! #include "boost/lambda/detail/is_instance_of.hpp" ! #include "boost/type_traits/same_traits.hpp" ! #include "boost/type_traits/cv_traits.hpp" ! #include "boost/type_traits/remove_reference.hpp" ! ! #include "boost/indirect_reference.hpp" ! ! #include <cstddef> // needed for the ptrdiff_t ! #include <iosfwd> // for istream and ostream ! ! #include <iterator> // needed for operator& ! ! namespace boost { ! namespace lambda { ! namespace detail { ! ! // -- general helper templates for type deduction ------------------ ! ! // Much of the type deduction code for standard arithmetic types from Gary Powell ! ! template <class A> struct promote_code { static const int value = -1; }; ! // this means that a code is not defined for A ! ! // -- the next 5 types are needed in if_then_else_return ! // the promotion order is not important, but they must have distinct values. ! template <> struct promote_code<bool> { static const int value = 10; }; ! template <> struct promote_code<char> { static const int value = 20; }; ! template <> struct promote_code<unsigned char> { static const int value = 30; }; ! template <> struct promote_code<signed char> { static const int value = 40; }; ! template <> struct promote_code<short int> { static const int value = 50; }; ! // ---------- ! ! template <> struct promote_code<int> { static const int value = 100; }; ! template <> struct promote_code<unsigned int> { static const int value = 200; }; ! template <> struct promote_code<long> { static const int value = 300; }; ! template <> struct promote_code<unsigned long> { static const int value = 400; }; ! ! template <> struct promote_code<float> { static const int value = 500; }; ! template <> struct promote_code<double> { static const int value = 600; }; ! template <> struct promote_code<long double> { static const int value = 700; }; ! ! // TODO: wchar_t ! ! // forward delcaration of complex. ! ! } // namespace detail ! } // namespace lambda ! } // namespace boost ! ! namespace std { ! template<class T> class complex; ! } ! ! namespace boost { ! namespace lambda { ! namespace detail { ! ! template <> struct promote_code< std::complex<float> > { static const int value = 800; }; ! template <> struct promote_code< std::complex<double> > { static const int value = 900; }; ! template <> struct promote_code< std::complex<long double> > { static const int value = 1000; }; ! ! // -- int promotion ------------------------------------------- ! template <class T> struct promote_to_int { typedef T type; }; ! ! template <> struct promote_to_int<bool> { typedef int type; }; ! template <> struct promote_to_int<char> { typedef int type; }; ! template <> struct promote_to_int<unsigned char> { typedef int type; }; ! template <> struct promote_to_int<signed char> { typedef int type; }; ! template <> struct promote_to_int<short int> { typedef int type; }; ! ! // The unsigned short int promotion rule is this: ! // unsigned short int to signed int if a signed int can hold all values ! // of unsigned short int, otherwise go to unsigned int. ! template <> struct promote_to_int<unsigned short int> ! { ! typedef ! detail::IF<sizeof(int) <= sizeof(unsigned short int), ! // I had the logic reversed but ">" messes up the parsing. ! unsigned int, ! int>::RET type; ! }; ! ! ! // TODO: think, should there be default behaviour for non-standard types? ! ! } // namespace detail ! ! // ------------------------------------------ ! // Unary actions ---------------------------- ! // ------------------------------------------ ! ! template<class Act, class A> ! struct plain_return_type_1 { ! typedef typename detail::IF_type<(is_const<A>::value || is_volatile<A>::value), ! plain_return_type_1<Act, typename remove_cv<A>::type>, ! detail::identity_mapping<detail::unspecified> ! >::type type; ! }; ! ! ! ! template<class Act, class A> ! struct plain_return_type_1<unary_arithmetic_action<Act>, A> { ! typedef A type; ! }; ! ! template<class Act, class A> ! struct return_type_1<unary_arithmetic_action<Act>, A> { ! typedef ! typename plain_return_type_1< ! unary_arithmetic_action<Act>, ! typename boost::remove_reference<A>::type ! >::type type; ! }; ! ! ! template<class A> ! struct plain_return_type_1<bitwise_action<not_action>, A> { ! typedef A type; ! }; ! ! // bitwise not, operator~() ! template<class A> struct return_type_1<bitwise_action<not_action>, A> { ! typedef ! typename plain_return_type_1< ! bitwise_action<not_action>, ! typename boost::remove_reference<A>::type ! >::type type; ! }; ! ! ! // prefix increment and decrement operators return ! // their argument by default as a non-const reference ! template<class Act, class A> ! struct plain_return_type_1<pre_increment_decrement_action<Act>, A> { ! typedef A& type; ! }; ! ! template<class Act, class A> ! struct return_type_1<pre_increment_decrement_action<Act>, A> { ! typedef ! typename plain_return_type_1< ! pre_increment_decrement_action<Act>, ! typename boost::remove_reference<A>::type ! >::type type; ! }; ! ! // post decrement just returns the same plain type. ! template<class Act, class A> ! struct plain_return_type_1<post_increment_decrement_action<Act>, A> { ! typedef A type; ! }; ! ! template<class Act, class A> ! struct return_type_1<post_increment_decrement_action<Act>, A> ! { ! typedef ! typename plain_return_type_1< ! post_increment_decrement_action<Act>, ! typename boost::remove_reference<A>::type ! >::type type; ! }; ! ! // logical not, operator!() ! template<class A> ! struct plain_return_type_1<logical_action<not_action>, A> { ! typedef bool type; ! }; ! ! template<class A> ! struct return_type_1<logical_action<not_action>, A> { ! typedef ! typename plain_return_type_1< ! logical_action<not_action>, ! typename boost::remove_reference<A>::type ! >::type type; ! }; ! ! // address of action --------------------------------------- ! ! ! template<class A> ! struct return_type_1<other_action<addressof_action>, A> { ! typedef ! typename plain_return_type_1< ! other_action<addressof_action>, ! typename boost::remove_reference<A>::type ! >::type type1; ! ! // If no user defined specialization for A, then return the ! // cv qualified pointer to A ! typedef typename detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::remove_reference<A>::type*, ! type1 ! >::RET type; ! }; ! ! // contentsof action ------------------------------------ ! ! // TODO: this deduction may lead to fail directly, ! // (if A has no specialization for iterator_traits and has no ! // typedef A::reference. ! // There is no easy way around this, cause there doesn't seem to be a way ! // to test whether a class is an iterator or not. ! ! // The default works with std::iterators. ! ! namespace detail { ! ! // A is a nonreference type ! template <class A> struct contentsof_type { ! typedef typename boost::indirect_reference<A>::type type; ! }; ! ! // this is since the nullary () in lambda_functor is always instantiated ! template <> struct contentsof_type<null_type> { ! typedef detail::unspecified type; ! }; ! ! ! template <class A> struct contentsof_type<const A> { ! typedef typename contentsof_type<A>::type type1; ! // return a reference to the underlying const type ! // the IF is because the A::reference in the primary template could ! // be some class type rather than a real reference, hence ! // we do not want to make it a reference here either ! typedef typename detail::IF< ! is_reference<type1>::value, ! const typename boost::remove_reference<type1>::type &, ! const type1 ! >::RET type; ! }; ! ! template <class A> struct contentsof_type<volatile A> { ! typedef typename contentsof_type<A>::type type1; ! typedef typename detail::IF< ! is_reference<type1>::value, ! volatile typename boost::remove_reference<type1>::type &, ! volatile type1 ! >::RET type; ! }; ! ! template <class A> struct contentsof_type<const volatile A> { ! typedef typename contentsof_type<A>::type type1; ! typedef typename detail::IF< ! is_reference<type1>::value, ! const volatile typename boost::remove_reference<type1>::type &, ! const volatile type1 ! >::RET type; ! }; ! ! // standard iterator traits should take care of the pointer types ! // but just to be on the safe side, we have the specializations here: ! // these work even if A is cv-qualified. ! template <class A> struct contentsof_type<A*> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* const> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* volatile> { ! typedef A& type; ! }; ! template <class A> struct contentsof_type<A* const volatile> { ! typedef A& type; ! }; ! ! template<class A, int N> struct contentsof_type<A[N]> { ! typedef A& type; ! }; ! template<class A, int N> struct contentsof_type<const A[N]> { ! typedef const A& type; ! }; ! template<class A, int N> struct contentsof_type<volatile A[N]> { ! typedef volatile A& type; ! }; ! template<class A, int N> struct contentsof_type<const volatile A[N]> { ! typedef const volatile A& type; ! }; ! ! ! ! ! ! } // end detail ! ! template<class A> ! struct return_type_1<other_action<contentsof_action>, A> { ! ! typedef ! typename plain_return_type_1< ! other_action<contentsof_action>, ! typename boost::remove_reference<A>::type ! >::type type1; ! ! // If no user defined specialization for A, then return the ! // cv qualified pointer to A ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::contentsof_type< ! typename boost::remove_reference<A>::type ! >, ! detail::identity_mapping<type1> ! >::type type; ! }; ! ! ! // ------------------------------------------------------------------ ! // binary actions --------------------------------------------------- ! // ------------------------------------------------------------------ ! ! // here the default case is: no user defined versions: ! template <class Act, class A, class B> ! struct plain_return_type_2 { ! typedef typename detail::IF_type<(is_const<A>::value || is_volatile<A>::value || is_const<B>::value || is_volatile<B>::value), ! plain_return_type_2<Act, typename remove_cv<A>::type, typename remove_cv<B>::type>, ! detail::identity_mapping<detail::unspecified> ! >::type type; ! }; ! ! namespace detail { ! ! // error classes ! class illegal_pointer_arithmetic{}; ! ! // pointer arithmetic type deductions ---------------------- ! // value = false means that this is not a pointer arithmetic case ! // value = true means, that this can be a pointer arithmetic case, but not necessarily is ! // This means, that for user defined operators for pointer types, say for some operator+(X, *Y), ! // the deductions must be coded at an earliel level (return_type_2). ! ! template<class Act, class A, class B> ! struct pointer_arithmetic_traits { static const bool value = false; }; ! ! template<class A, class B> ! struct pointer_arithmetic_traits<plus_action, A, B> { ! ! typedef typename ! array_to_pointer<typename boost::remove_reference<A>::type>::type AP; ! typedef typename ! array_to_pointer<typename boost::remove_reference<B>::type>::type BP; ! ! static const bool is_pointer_A = boost::is_pointer<AP>::value; ! static const bool is_pointer_B = boost::is_pointer<BP>::value; ! ! static const bool value = is_pointer_A || is_pointer_B; ! ! // can't add two pointers. ! // note, that we do not check wether the other type is valid for ! // addition with a pointer. ! // the compiler will catch it in the apply function ! ! typedef typename ! detail::IF< ! is_pointer_A && is_pointer_B, ! detail::return_type_deduction_failure< ! detail::illegal_pointer_arithmetic ! >, ! typename detail::IF<is_pointer_A, AP, BP>::RET ! >::RET type; ! ! }; ! ! template<class A, class B> ! struct pointer_arithmetic_traits<minus_action, A, B> { ! typedef typename ! array_to_pointer<typename boost::remove_reference<A>::type>::type AP; ! typedef typename ! array_to_pointer<typename boost::remove_reference<B>::type>::type BP; ! ! static const bool is_pointer_A = boost::is_pointer<AP>::value; ! static const bool is_pointer_B = boost::is_pointer<BP>::value; ! ! static const bool value = is_pointer_A || is_pointer_B; ! ! static const bool same_pointer_type = ! is_pointer_A && is_pointer_B && ! boost::is_same< ! typename boost::remove_const< ! typename boost::remove_pointer< ! typename boost::remove_const<AP>::type ! >::type ! >::type, ! typename boost::remove_const< ! typename boost::remove_pointer< ! typename boost::remove_const<BP>::type ! >::type ! >::type ! >::value; ! ! // ptr - ptr has type ptrdiff_t ! // note, that we do not check if, in ptr - B, B is ! // valid for subtraction with a pointer. ! // the compiler will catch it in the apply function ! ! typedef typename ! detail::IF< ! same_pointer_type, const std::ptrdiff_t, ! typename detail::IF< ! is_pointer_A, ! AP, ! detail::return_type_deduction_failure<detail::illegal_pointer_arithmetic> ! >::RET ! >::RET type; ! }; ! ! } // namespace detail ! ! // -- arithmetic actions --------------------------------------------- ! ! namespace detail { ! ! template<bool is_pointer_arithmetic, class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1; ! ! template<class A, class B> struct return_type_2_arithmetic_phase_2; ! template<class A, class B> struct return_type_2_arithmetic_phase_3; ! ! } // namespace detail ! ! ! // drop any qualifiers from the argument types within arithmetic_action ! template<class A, class B, class Act> ! struct return_type_2<arithmetic_action<Act>, A, B> ! { ! typedef typename remove_reference<A>::type plain_A; ! typedef typename remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter the whole arithmetic deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::return_type_2_arithmetic_phase_1< ! detail::pointer_arithmetic_traits<Act, A, B>::value, Act, A, B ! >, ! plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B> ! >::type type; ! }; ! ! namespace detail { ! ! // perform integral promotion, no pointer arithmetic ! template<bool is_pointer_arithmetic, class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1 ! { ! typedef typename ! return_type_2_arithmetic_phase_2< ! typename remove_reference_and_cv<A>::type, ! typename remove_reference_and_cv<B>::type ! >::type type; ! }; ! ! // pointer_arithmetic ! template<class Act, class A, class B> ! struct return_type_2_arithmetic_phase_1<true, Act, A, B> ! { ! typedef typename ! pointer_arithmetic_traits<Act, A, B>::type type; ! }; ! ! template<class A, class B> ! struct return_type_2_arithmetic_phase_2 { ! typedef typename ! return_type_2_arithmetic_phase_3< ! typename promote_to_int<A>::type, ! typename promote_to_int<B>::type ! >::type type; ! }; ! ! // specialization for unsigned int. ! // We only have to do these two specialization because the value promotion will ! // take care of the other cases. ! // The unsigned int promotion rule is this: ! // unsigned int to long if a long can hold all values of unsigned int, ! // otherwise go to unsigned long. ! ! // struct so I don't have to type this twice. ! struct promotion_of_unsigned_int ! { ! typedef ! detail::IF<sizeof(long) <= sizeof(unsigned int), ! unsigned long, ! long>::RET type; ! }; ! ! template<> ! struct return_type_2_arithmetic_phase_2<unsigned int, long> ! { ! typedef promotion_of_unsigned_int::type type; ! }; ! template<> ! struct return_type_2_arithmetic_phase_2<long, unsigned int> ! { ! typedef promotion_of_unsigned_int::type type; ! }; ! ! ! template<class A, class B> struct return_type_2_arithmetic_phase_3 { ! enum { promote_code_A_value = promote_code<A>::value, ! promote_code_B_value = promote_code<B>::value }; // enums for KCC ! typedef typename ! detail::IF< ! promote_code_A_value == -1 || promote_code_B_value == -1, ! detail::return_type_deduction_failure<return_type_2_arithmetic_phase_3>, ! typename detail::IF< ! ((int)promote_code_A_value > (int)promote_code_B_value), ! A, ! B ! >::RET ! >::RET type; ! }; ! ! } // namespace detail ! ! // -- bitwise actions ------------------------------------------- ! // note: for integral types deuduction is similar to arithmetic actions. ! ! // drop any qualifiers from the argument types within arithmetic action ! template<class A, class B, class Act> ! struct return_type_2<bitwise_action<Act>, A, B> ! { ! ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<Act>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! return_type_2<arithmetic_action<plus_action>, A, B>, ! plain_return_type_2<bitwise_action<Act>, plain_A, plain_B> ! >::type type; ! ! // plus_action is just a random pick, has to be a concrete instance ! ! // TODO: This check is only valid for built-in types, overloaded types might ! // accept floating point operators ! ! // bitwise operators not defined for floating point types ! // these test are not strictly needed here, since the error will be caught in ! // the apply function ! BOOST_STATIC_ASSERT(!(boost::is_float<plain_A>::value && boost::is_float<plain_B>::value)); ! ! }; ! ! namespace detail { ! ! #ifdef BOOST_NO_TEMPLATED_STREAMS ! ! template<class A, class B> ! struct leftshift_type { ! ! typedef typename detail::IF< ! boost::is_convertible< ! typename boost::remove_reference<A>::type*, ! std::ostream* ! >::value, ! std::ostream&, ! typename detail::remove_reference_and_cv<A>::type ! >::RET type; ! }; ! ! template<class A, class B> ! struct rightshift_type { ! ! typedef typename detail::IF< ! ! boost::is_convertible< ! typename boost::remove_reference<A>::type*, ! std::istream* ! >::value, ! std::istream&, ! typename detail::remove_reference_and_cv<A>::type ! >::RET type; ! }; ! ! #else ! ! template <class T> struct get_ostream_type { ! typedef std::basic_ostream<typename T::char_type, ! typename T::traits_type>& type; ! }; ! ! template <class T> struct get_istream_type { ! typedef std::basic_istream<typename T::char_type, ! typename T::traits_type>& type; ! }; ! ! template<class A, class B> ! struct leftshift_type { ! private: ! typedef typename boost::remove_reference<A>::type plainA; ! public: ! typedef typename detail::IF_type< ! is_instance_of_2<plainA, std::basic_ostream>::value, ! get_ostream_type<plainA>, //reference to the stream ! detail::remove_reference_and_cv<A> ! >::type type; ! }; ! ! template<class A, class B> ! struct rightshift_type { ! private: ! typedef typename boost::remove_reference<A>::type plainA; ! public: ! typedef typename detail::IF_type< ! is_instance_of_2<plainA, std::basic_istream>::value, ! get_istream_type<plainA>, //reference to the stream ! detail::remove_reference_and_cv<A> ! >::type type; ! }; ! ! ! #endif ! ! } // end detail ! ! // ostream ! template<class A, class B> ! struct return_type_2<bitwise_action<leftshift_action>, A, B> ! { ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::leftshift_type<A, B>, ! plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B> ! >::type type; ! }; ! ! // istream ! template<class A, class B> ! struct return_type_2<bitwise_action<rightshift_action>, A, B> ! { ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B>::type type1; ! ! // if user defined return type, do not enter type deductions ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::rightshift_type<A, B>, ! plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B> ! >::type type; ! }; ! ! // -- logical actions ---------------------------------------- ! // always bool ! // NOTE: this may not be true for some weird user-defined types, ! template<class A, class B, class Act> ! struct plain_return_type_2<logical_action<Act>, A, B> { ! typedef bool type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<logical_action<Act>, A, B> { ! ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<logical_action<Act>, plain_A, plain_B>::type type; ! ! }; ! ! ! // -- relational actions ---------------------------------------- ! // always bool ! // NOTE: this may not be true for some weird user-defined types, ! template<class A, class B, class Act> ! struct plain_return_type_2<relational_action<Act>, A, B> { ! typedef bool type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<relational_action<Act>, A, B> { ! ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2<relational_action<Act>, plain_A, plain_B>::type type; ! }; ! ! // Assingment actions ----------------------------------------------- ! // return type is the type of the first argument as reference ! ! // note that cv-qualifiers are preserved. ! // Yes, assignment operator can be const! ! ! // NOTE: this may not be true for some weird user-defined types, ! ! template<class A, class B, class Act> ! struct return_type_2<arithmetic_assignment_action<Act>, A, B> { ! ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! arithmetic_assignment_action<Act>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! template<class A, class B, class Act> ! struct return_type_2<bitwise_assignment_action<Act>, A, B> { ! ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! bitwise_assignment_action<Act>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! template<class A, class B> ! struct return_type_2<other_action<assignment_action>, A, B> { ! typedef typename boost::remove_reference<A>::type plain_A; ! typedef typename boost::remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! other_action<assignment_action>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF< ! boost::is_same<type1, detail::unspecified>::value, ! typename boost::add_reference<A>::type, ! type1 ! >::RET type; ! }; ! ! // -- other actions ---------------------------------------- ! ! // comma action ---------------------------------- ! // Note: this may not be true for some weird user-defined types, ! ! // NOTE! This only tries the plain_return_type_2 layer and gives ! // detail::unspecified as default. If no such specialization is found, the ! // type rule in the spcecialization of the return_type_2_prot is used ! // to give the type of the right argument (which can be a reference too) ! // (The built in operator, can return a l- or rvalue). ! template<class A, class B> ! struct return_type_2<other_action<comma_action>, A, B> { ! ! typedef typename remove_reference<A>::type plain_A; ! typedef typename remove_reference<B>::type plain_B; ! ! typedef typename ! plain_return_type_2< ! other_action<comma_action>, plain_A, plain_B ! >::type type; ! }; ! ! // subscript action ----------------------------------------------- ! ! ! namespace detail { ! // A and B are nonreference types ! template <class A, class B> struct subscript_type { ! typedef detail::unspecified type; ! }; ! ! template <class A, class B> struct subscript_type<A*, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* const, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* volatile, B> { ! typedef A& type; ! }; ! template <class A, class B> struct subscript_type<A* const volatile, B> { ! typedef A& type; ! }; ! ! ! template<class A, class B, int N> struct subscript_type<A[N], B> { ! typedef A& type; ! }; ! ! // these 3 specializations are needed to make gcc <3 happy ! template<class A, class B, int N> struct subscript_type<const A[N], B> { ! typedef const A& type; ! }; ! template<class A, class B, int N> struct subscript_type<volatile A[N], B> { ! typedef volatile A& type; ! }; ! template<class A, class B, int N> struct subscript_type<const volatile A[N], B> { ! typedef const volatile A& type; ! }; ! ! } // end detail ! ! template<class A, class B> ! struct return_type_2<other_action<subscript_action>, A, B> { ! ! typedef typename remove_reference<A>::type plain_A; ! typedef typename remove_reference<B>::type plain_B; ! ! typedef typename boost::remove_reference<A>::type nonref_A; ! typedef typename boost::remove_reference<B>::type nonref_B; ! ! typedef typename ! plain_return_type_2< ! other_action<subscript_action>, plain_A, plain_B ! >::type type1; ! ! typedef typename ! detail::IF_type< ! boost::is_same<type1, detail::unspecified>::value, ! detail::subscript_type<nonref_A, nonref_B>, ! plain_return_type_2<other_action<subscript_action>, plain_A, plain_B> ! >::type type; ! ! }; ! ! ! } // namespace lambda ! } // namespace boost ! ! ! // Forward declarations are incompatible with the libstdc++ debug mode. ! #if BOOST_WORKAROUND(__GNUC__, >= 3) && defined(_GLIBCXX_DEBUG) ! #include <string> ! #include <vector> ! #include <map> ! #include <deque> ! #else ! ! // The GCC 2.95.x uses a non-conformant deque ! #if BOOST_WORKAROUND(__GNUC__, == 2) && __GNUC_MINOR__ <= 96 ! #include <deque> ! #else ! ! namespace std { ! template <class T, class Allocator> class deque; ! } ! ! #endif ! ! namespace std { ! template <class Char, class Traits, class Allocator> class basic_string; ! template <class T, class Allocator> class vector; ! template <class Key, class T, class Cmp, class Allocator> class map; ! template <class Key, class T, class Cmp, class Allocator> class multimap; ! } ! ! #endif ! ! ! namespace boost { ! template <class T, std::size_t N> class array; ! } ! ! ! namespace boost { ! namespace lambda { ! ! template<class Key, class T, class Cmp, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::map<Key, T, Cmp, Allocator>, B> { ! typedef T& type; ! // T == std::map<Key, T, Cmp, Allocator>::mapped_type; ! }; ! ! template<class Key, class T, class Cmp, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::multimap<Key, T, Cmp, Allocator>, B> { ! typedef T& type; ! // T == std::map<Key, T, Cmp, Allocator>::mapped_type; ! }; ! ! // deque ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::deque<T, Allocator>, B> { ! typedef typename std::deque<T, Allocator>::reference type; ! }; ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::deque<T, Allocator>, B> { ! typedef typename std::deque<T, Allocator>::const_reference type; ! }; ! ! // vector ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::vector<T, Allocator>, B> { ! typedef typename std::vector<T, Allocator>::reference type; ! }; ! template<class T, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::vector<T, Allocator>, B> { ! typedef typename std::vector<T, Allocator>::const_reference type; ! }; ! ! // basic_string ! template<class Char, class Traits, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, std::basic_string<Char, Traits, Allocator>, B> { ! typedef typename std::basic_string<Char, Traits, Allocator>::reference type; ! }; ! template<class Char, class Traits, class Allocator, class B> ! struct plain_return_type_2<other_action<subscript_action>, const std::basic_string<Char, Traits, Allocator>, B> { ! typedef typename std::basic_string<Char, Traits, Allocator>::const_reference type; ! }; ! ! template<class T, int N, class B> ! struct return_type_2<other_action<subscript_action>, boost::array<T, N>, B> { ! typedef typename boost::array<T, N>::reference type; ! }; ! template<class T, int N, class B> ! struct return_type_2<other_action<subscript_action>, const boost::array<T, N>, B> { ! typedef typename boost::array<T, N>::const_reference type; ! }; ! ! ! // -- plus_action for basic_string ----------------------------------------------------------------- ! template<class Char, class Traits> ! struct plain_return_type_2<arithmetic_action<plus_action>, std::basic_string<Char, Traits>, std::basic_string<Char, Traits> > { ! typedef std::basic_string<Char, Traits> type; ! }; ! // -- pointer versions ----------------------------------------------------------------------------- ! template<class Char, class Traits> ! struct plain_return_type_2<arithmetic_action<plus_action>, std::basic_string<Char, Traits>, Char*> { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits> ! struct plain_return_type_2<arithmetic_action<plus_action>, std::basic_string<Char, Traits>, const Char*> { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits> ! struct plain_return_type_2<Char*, arithmetic_action<plus_action>, std::basic_string<Char, Traits> > { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits> ! struct plain_return_type_2<const Char*, arithmetic_action<plus_action>, std::basic_string<Char, Traits> > { ! typedef std::basic_string<Char, Traits> type; ! }; ! // -- array versions --------------------------------------------------------------------------------- ! template<class Char, class Traits, int N> ! struct plain_return_type_2<arithmetic_action<plus_action>, std::basic_string<Char, Traits>, Char[N]> { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits, int N> ! struct plain_return_type_2<arithmetic_action<plus_action>, std::basic_string<Char, Traits>, const Char[N]> { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits, int N> ! struct plain_return_type_2<Char[N], arithmetic_action<plus_action>, std::basic_string<Char, Traits> > { ! typedef std::basic_string<Char, Traits> type; ! }; ! template<class Char, class Traits, int N> ! struct plain_return_type_2<const Char[N], arithmetic_action<plus_action>, std::basic_string<Char, Traits> > { ! typedef std::basic_string<Char, Traits> type; ! }; ! ! ! } // namespace lambda ! } // namespace boost ! ! #endif ! !