| // Copyright Cromwell D. Enage 2018. |
| // 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) |
| |
| #include <boost/parameter/config.hpp> |
| |
| #if !defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING) && \ |
| (BOOST_PARAMETER_COMPOSE_MAX_ARITY < 3) |
| #error Define BOOST_PARAMETER_COMPOSE_MAX_ARITY as 3 or greater. |
| #endif |
| |
| #include <boost/parameter/name.hpp> |
| |
| namespace test { |
| |
| BOOST_PARAMETER_NAME(a0) |
| BOOST_PARAMETER_NAME(a1) |
| BOOST_PARAMETER_NAME(a2) |
| } |
| |
| #if !defined(BOOST_NO_SFINAE) |
| #include <boost/parameter/is_argument_pack.hpp> |
| #include <boost/type_traits/is_convertible.hpp> |
| #include <boost/core/enable_if.hpp> |
| #endif |
| |
| namespace test { |
| |
| #if !defined(BOOST_NO_SFINAE) |
| struct _enabler |
| { |
| }; |
| #endif |
| |
| template <typename T> |
| class backend0 |
| { |
| T _a0; |
| |
| public: |
| template <typename ArgPack> |
| explicit backend0( |
| ArgPack const& args |
| #if !defined(BOOST_NO_SFINAE) |
| , typename boost::enable_if< |
| boost::parameter::is_argument_pack<ArgPack> |
| , test::_enabler |
| >::type = test::_enabler() |
| #endif |
| ) : _a0(args[test::_a0]) |
| { |
| } |
| |
| #if !defined(BOOST_NO_SFINAE) |
| template <typename U> |
| backend0( |
| backend0<U> const& copy |
| , typename boost::enable_if< |
| boost::is_convertible<U,T> |
| , test::_enabler |
| >::type = test::_enabler() |
| ) : _a0(copy.get_a0()) |
| { |
| } |
| #endif |
| |
| template <typename Iterator> |
| backend0(Iterator itr, Iterator itr_end) : _a0(itr, itr_end) |
| { |
| } |
| |
| T const& get_a0() const |
| { |
| return this->_a0; |
| } |
| |
| protected: |
| template <typename ArgPack> |
| void initialize_impl(ArgPack const& args) |
| { |
| this->_a0 = args[test::_a0]; |
| } |
| }; |
| |
| template <typename B, typename T> |
| class backend1 : public B |
| { |
| T _a1; |
| |
| public: |
| template <typename ArgPack> |
| explicit backend1( |
| ArgPack const& args |
| #if !defined(BOOST_NO_SFINAE) |
| , typename boost::enable_if< |
| boost::parameter::is_argument_pack<ArgPack> |
| , test::_enabler |
| >::type = test::_enabler() |
| #endif |
| ) : B(args), _a1(args[test::_a1]) |
| { |
| } |
| |
| #if !defined(BOOST_NO_SFINAE) |
| template <typename Derived> |
| backend1( |
| Derived const& copy |
| , typename boost::disable_if< |
| boost::parameter::is_argument_pack<Derived> |
| , test::_enabler |
| >::type = test::_enabler() |
| ) : B(copy), _a1(copy.get_a1()) |
| { |
| } |
| #endif |
| |
| T const& get_a1() const |
| { |
| return this->_a1; |
| } |
| |
| protected: |
| template <typename ArgPack> |
| void initialize_impl(ArgPack const& args) |
| { |
| B::initialize_impl(args); |
| this->_a1 = args[test::_a1]; |
| } |
| }; |
| |
| template <typename B, typename T> |
| class backend2 : public B |
| { |
| T _a2; |
| |
| public: |
| template <typename ArgPack> |
| explicit backend2( |
| ArgPack const& args |
| #if !defined(BOOST_NO_SFINAE) |
| , typename boost::enable_if< |
| boost::parameter::is_argument_pack<ArgPack> |
| , test::_enabler |
| >::type = test::_enabler() |
| #endif |
| ) : B(args), _a2(args[test::_a2]) |
| { |
| } |
| |
| #if !defined(BOOST_NO_SFINAE) |
| template <typename Derived> |
| backend2( |
| Derived const& copy |
| , typename boost::disable_if< |
| boost::parameter::is_argument_pack<Derived> |
| , test::_enabler |
| >::type = test::_enabler() |
| ) : B(copy), _a2(copy.get_a2()) |
| { |
| } |
| #endif |
| |
| T const& get_a2() const |
| { |
| return this->_a2; |
| } |
| |
| protected: |
| template <typename ArgPack> |
| void initialize_impl(ArgPack const& args) |
| { |
| B::initialize_impl(args); |
| this->_a2 = args[test::_a2]; |
| } |
| }; |
| } |
| |
| #include <boost/parameter/preprocessor_no_spec.hpp> |
| |
| #if !defined(BOOST_NO_SFINAE) |
| #include <boost/parameter/are_tagged_arguments.hpp> |
| #endif |
| |
| namespace test { |
| |
| template <typename B> |
| struct frontend : public B |
| { |
| BOOST_PARAMETER_NO_SPEC_CONSTRUCTOR(frontend, (B)) |
| |
| #if !defined(BOOST_NO_SFINAE) |
| template <typename Iterator> |
| frontend( |
| Iterator itr |
| , Iterator itr_end |
| , typename boost::disable_if< |
| boost::parameter::are_tagged_arguments<Iterator> |
| , test::_enabler |
| >::type = test::_enabler() |
| ) : B(itr, itr_end) |
| { |
| } |
| |
| template <typename O> |
| frontend(frontend<O> const& copy) : B(copy) |
| { |
| } |
| #endif |
| |
| BOOST_PARAMETER_NO_SPEC_MEMBER_FUNCTION((void), initialize) |
| { |
| this->initialize_impl(args); |
| } |
| |
| BOOST_PARAMETER_NO_SPEC_FUNCTION_CALL_OPERATOR((void)) |
| { |
| this->initialize_impl(args); |
| } |
| }; |
| } // namespace test |
| |
| #include <boost/core/lightweight_test.hpp> |
| |
| #if !defined(BOOST_NO_SFINAE) |
| #include <string> |
| #endif |
| |
| int main() |
| { |
| char const* p = "foo"; |
| char const* q = "bar"; |
| test::frontend< |
| test::backend2<test::backend1<test::backend0<char const*>, char>, int> |
| > composed_obj0(test::_a2 = 4, test::_a1 = ' ', test::_a0 = p); |
| #if defined(BOOST_NO_SFINAE) |
| test::frontend< |
| test::backend1<test::backend2<test::backend0<char const*>, int>, char> |
| > composed_obj1(test::_a0 = p, test::_a1 = ' ', test::_a2 = 4); |
| #else |
| test::frontend< |
| test::backend1<test::backend2<test::backend0<char const*>, int>, char> |
| > composed_obj1(composed_obj0); |
| #endif |
| BOOST_TEST_EQ(composed_obj0.get_a0(), composed_obj1.get_a0()); |
| BOOST_TEST_EQ(composed_obj0.get_a1(), composed_obj1.get_a1()); |
| BOOST_TEST_EQ(composed_obj0.get_a2(), composed_obj1.get_a2()); |
| composed_obj0.initialize(test::_a0 = q, test::_a1 = '!', test::_a2 = 8); |
| composed_obj1.initialize(test::_a2 = 8, test::_a1 = '!', test::_a0 = q); |
| BOOST_TEST_EQ(composed_obj0.get_a0(), composed_obj1.get_a0()); |
| BOOST_TEST_EQ(composed_obj0.get_a1(), composed_obj1.get_a1()); |
| BOOST_TEST_EQ(composed_obj0.get_a2(), composed_obj1.get_a2()); |
| composed_obj0(test::_a2 = 8, test::_a1 = '!', test::_a0 = q); |
| composed_obj1(test::_a0 = q, test::_a1 = '!', test::_a2 = 8); |
| BOOST_TEST_EQ(composed_obj0.get_a0(), composed_obj1.get_a0()); |
| BOOST_TEST_EQ(composed_obj0.get_a1(), composed_obj1.get_a1()); |
| BOOST_TEST_EQ(composed_obj0.get_a2(), composed_obj1.get_a2()); |
| #if !defined(BOOST_NO_SFINAE) |
| test::frontend<test::backend0<std::string> > string_wrap(p, p + 3); |
| BOOST_TEST_EQ(string_wrap.get_a0(), std::string(p)); |
| #endif |
| return boost::report_errors(); |
| } |
| |