| // Copyright Cromwell D. Enage 2019. |
| // 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) |
| |
| #ifndef BOOST_PARAMETER_AUX_HAS_NESTED_TEMPLATE_FN_HPP |
| #define BOOST_PARAMETER_AUX_HAS_NESTED_TEMPLATE_FN_HPP |
| |
| #include <boost/parameter/aux_/yesno.hpp> |
| #include <boost/parameter/aux_/preprocessor/nullptr.hpp> |
| #include <boost/parameter/config.hpp> |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| #include <boost/mp11/integral.hpp> |
| #include <boost/mp11/utility.hpp> |
| #else |
| #include <boost/mpl/bool.hpp> |
| #include <boost/mpl/identity.hpp> |
| #endif |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| template <template <typename ...> class F> |
| struct has_nested_template_fn_variadic |
| { |
| }; |
| #else |
| template <template <typename P0, typename P1> class F> |
| struct has_nested_template_fn_arity_2 |
| { |
| }; |
| #endif |
| |
| template <typename T> |
| class has_nested_template_fn_impl |
| { |
| template <typename U> |
| static ::boost::parameter::aux::no_tag _check(...); |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| template <typename U> |
| static ::boost::parameter::aux::yes_tag |
| _check( |
| ::boost::mp11::mp_identity<U> const volatile* |
| , ::boost::parameter::aux::has_nested_template_fn_variadic< |
| U::template fn |
| >* = BOOST_PARAMETER_AUX_PP_NULLPTR |
| ); |
| #else |
| template <typename U> |
| static BOOST_CONSTEXPR ::boost::parameter::aux::yes_tag |
| _check( |
| ::boost::mpl::identity<U> const volatile* |
| , ::boost::parameter::aux::has_nested_template_fn_arity_2< |
| U::template fn |
| >* = BOOST_PARAMETER_AUX_PP_NULLPTR |
| ); |
| #endif |
| |
| public: |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| using type = ::boost::mp11::mp_bool< |
| #else |
| typedef ::boost::mpl::bool_< |
| #endif |
| sizeof( |
| ::boost::parameter::aux::has_nested_template_fn_impl<T> |
| ::template _check<T>( |
| static_cast< |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| ::boost::mp11::mp_identity<T> const volatile* |
| #else |
| ::boost::mpl::identity<T> const volatile* |
| #endif |
| >(BOOST_PARAMETER_AUX_PP_NULLPTR) |
| ) |
| ) == sizeof(::boost::parameter::aux::yes_tag) |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| >; |
| #else |
| > type; |
| #endif |
| }; |
| }}} // namespace boost::parameter::aux |
| |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| #include <type_traits> |
| #else |
| #include <boost/type_traits/remove_const.hpp> |
| #endif |
| |
| namespace boost { namespace parameter { namespace aux { |
| |
| template <typename T> |
| #if defined(BOOST_PARAMETER_CAN_USE_MP11) |
| using has_nested_template_fn = typename ::boost::parameter::aux |
| ::has_nested_template_fn_impl<typename ::std::remove_const<T>::type> |
| ::type; |
| #else |
| struct has_nested_template_fn |
| : ::boost::parameter::aux::has_nested_template_fn_impl< |
| typename ::boost::remove_const<T>::type |
| >::type |
| { |
| }; |
| #endif |
| }}} // namespace boost::parameter::aux |
| |
| #endif // include guard |
| |