1 /*! 2 @file 3 Defines `boost::hana::and_`. 4 5 @copyright Louis Dionne 2013-2017 6 Distributed under the Boost Software License, Version 1.0. 7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) 8 */ 9 10 #ifndef BOOST_HANA_AND_HPP 11 #define BOOST_HANA_AND_HPP 12 13 #include <boost/hana/fwd/and.hpp> 14 15 #include <boost/hana/concept/logical.hpp> 16 #include <boost/hana/config.hpp> 17 #include <boost/hana/core/dispatch.hpp> 18 #include <boost/hana/detail/variadic/foldl1.hpp> 19 #include <boost/hana/if.hpp> 20 21 22 BOOST_HANA_NAMESPACE_BEGIN 23 //! @cond 24 template <typename X, typename Y> operator ()(X && x,Y && y) const25 constexpr decltype(auto) and_t::operator()(X&& x, Y&& y) const { 26 using Bool = typename hana::tag_of<X>::type; 27 using And = BOOST_HANA_DISPATCH_IF(and_impl<Bool>, 28 hana::Logical<Bool>::value 29 ); 30 31 #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS 32 static_assert(hana::Logical<Bool>::value, 33 "hana::and_(x, y) requires 'x' to be a Logical"); 34 #endif 35 36 return And::apply(static_cast<X&&>(x), static_cast<Y&&>(y)); 37 } 38 39 template <typename X, typename ...Y> operator ()(X && x,Y &&...y) const40 constexpr decltype(auto) and_t::operator()(X&& x, Y&& ...y) const { 41 return detail::variadic::foldl1( 42 *this, 43 static_cast<X&&>(x), 44 static_cast<Y&&>(y)... 45 ); 46 } 47 //! @endcond 48 49 template <typename L, bool condition> 50 struct and_impl<L, when<condition>> : default_ { 51 template <typename X, typename Y> applyand_impl52 static constexpr decltype(auto) apply(X&& x, Y&& y) { 53 return hana::if_(x, static_cast<Y&&>(y), x); 54 } 55 }; 56 BOOST_HANA_NAMESPACE_END 57 58 #endif // !BOOST_HANA_AND_HPP 59