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/*! @file Forward declares `boost::hana::and_`. Copyright Louis Dionne 2013-2022 Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) */ #ifndef BOOST_HANA_FWD_AND_HPP #define BOOST_HANA_FWD_AND_HPP #include <boost/hana/config.hpp> #include <boost/hana/core/when.hpp> namespace boost { namespace hana { //! Return whether all the arguments are true-valued. //! @ingroup group-Logical //! //! `and_` can be called with one argument or more. When called with //! two arguments, `and_` uses tag-dispatching to find the right //! implementation. Otherwise, //! @code //! and_(x) == x //! and_(x, y, ...z) == and_(and_(x, y), z...) //! @endcode //! //! //! Example //! ------- //! @include example/and.cpp #ifdef BOOST_HANA_DOXYGEN_INVOKED constexpr auto and_ = [](auto&& x, auto&& ...y) -> decltype(auto) { return tag-dispatched; }; #else template <typename L, typename = void> struct and_impl : and_impl<L, when<true>> { }; struct and_t { template <typename X, typename Y> constexpr decltype(auto) operator()(X&& x, Y&& y) const; template <typename X, typename ...Y> constexpr decltype(auto) operator()(X&& x, Y&& ...y) const; }; BOOST_HANA_INLINE_VARIABLE constexpr and_t and_{}; #endif }} // end namespace boost::hana #endif // !BOOST_HANA_FWD_AND_HPP