1 /*!
2 @file
3 Defines `boost::hana::adjust`.
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_ADJUST_HPP
11 #define BOOST_HANA_ADJUST_HPP
12 
13 #include <boost/hana/fwd/adjust.hpp>
14 
15 #include <boost/hana/adjust_if.hpp>
16 #include <boost/hana/concept/functor.hpp>
17 #include <boost/hana/config.hpp>
18 #include <boost/hana/core/dispatch.hpp>
19 #include <boost/hana/equal.hpp>
20 
21 
22 BOOST_HANA_NAMESPACE_BEGIN
23     //! @cond
24     template <typename Xs, typename Value, typename F>
operator ()(Xs && xs,Value && value,F && f) const25     constexpr auto adjust_t::operator()(Xs&& xs, Value&& value, F&& f) const {
26         using S = typename hana::tag_of<Xs>::type;
27         using Adjust = BOOST_HANA_DISPATCH_IF(adjust_impl<S>,
28             hana::Functor<S>::value
29         );
30 
31     #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
32         static_assert(hana::Functor<S>::value,
33         "hana::adjust(xs, value, f) requires 'xs' to be a Functor");
34     #endif
35 
36         return Adjust::apply(static_cast<Xs&&>(xs),
37                              static_cast<Value&&>(value),
38                              static_cast<F&&>(f));
39     }
40     //! @endcond
41 
42     template <typename Fun, bool condition>
43     struct adjust_impl<Fun, when<condition>> : default_ {
44         template <typename Xs, typename Value, typename F>
applyadjust_impl45         static constexpr auto apply(Xs&& xs, Value&& value, F&& f) {
46             return hana::adjust_if(
47                 static_cast<Xs&&>(xs),
48                 hana::equal.to(static_cast<Value&&>(value)),
49                 static_cast<F&&>(f)
50             );
51         }
52     };
53 BOOST_HANA_NAMESPACE_END
54 
55 #endif // !BOOST_HANA_ADJUST_HPP
56