boost/hana/adjust.hpp

0001 /*!
0002 @file
0003 Defines `boost::hana::adjust`.
0004
0005 Copyright Louis Dionne 2013-2022
0006 Distributed under the Boost Software License, Version 1.0.
0007 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
0008  */
0009
0010 #ifndef BOOST_HANA_ADJUST_HPP
0011 #define BOOST_HANA_ADJUST_HPP
0012
0013 #include <boost/hana/fwd/adjust.hpp>
0014
0015 #include <boost/hana/adjust_if.hpp>
0016 #include <boost/hana/concept/functor.hpp>
0017 #include <boost/hana/config.hpp>
0018 #include <boost/hana/core/dispatch.hpp>
0019 #include <boost/hana/equal.hpp>
0020
0021
0022 namespace boost { namespace hana {
0023     //! @cond
0024     template <typename Xs, typename Value, typename F>
0025     constexpr auto adjust_t::operator()(Xs&& xs, Value&& value, F&& f) const {
0026         using S = typename hana::tag_of<Xs>::type;
0027         using Adjust = BOOST_HANA_DISPATCH_IF(adjust_impl<S>,
0028             hana::Functor<S>::value
0029         );
0030
0031     #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
0032         static_assert(hana::Functor<S>::value,
0033         "hana::adjust(xs, value, f) requires 'xs' to be a Functor");
0034     #endif
0035
0036         return Adjust::apply(static_cast<Xs&&>(xs),
0037                              static_cast<Value&&>(value),
0038                              static_cast<F&&>(f));
0039     }
0040     //! @endcond
0041
0042     template <typename Fun, bool condition>
0043     struct adjust_impl<Fun, when<condition>> : default_ {
0044         template <typename Xs, typename Value, typename F>
0045         static constexpr auto apply(Xs&& xs, Value&& value, F&& f) {
0046             return hana::adjust_if(
0047                 static_cast<Xs&&>(xs),
0048                 hana::equal.to(static_cast<Value&&>(value)),
0049                 static_cast<F&&>(f)
0050             );
0051         }
0052     };
0053 }} // end namespace boost::hana
0054
0055 #endif // !BOOST_HANA_ADJUST_HPP