1/*!
2@file
3Forward declares `boost::hana::replace`.
4
5Copyright Louis Dionne 2013-2022
6Distributed 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_FWD_REPLACE_HPP
11#define BOOST_HANA_FWD_REPLACE_HPP
12
13#include <boost/hana/config.hpp>
14#include <boost/hana/core/when.hpp>
15
16
17namespace boost { namespace hana {
18 //! Replace all the elements of a structure that compare equal
19 //! to some `value` with some new fixed value.
20 //! @ingroup group-Functor
21 //!
22 //!
23 //! Signature
24 //! ---------
25 //! Given `F` a Functor and `U` a type that can be compared with `T`,
26 //! the signature is
27 //! \f$
28 //! \mathtt{replace} : F(T) \times U \times T \to F(T)
29 //! \f$
30 //!
31 //! @param xs
32 //! The structure to replace elements of.
33 //!
34 //! @param oldval
35 //! An object compared with each element of the structure. Elements
36 //! of the structure that compare equal to `oldval` are replaced
37 //! by `newval` in the new structure.
38 //!
39 //! @param newval
40 //! A value by which every element `x` of the structure that compares
41 //! equal to `oldval` is replaced.
42 //!
43 //!
44 //! Example
45 //! -------
46 //! @include example/replace.cpp
47#ifdef BOOST_HANA_DOXYGEN_INVOKED
48 constexpr auto replace = [](auto&& xs, auto&& oldval, auto&& newval) {
49 return tag-dispatched;
50 };
51#else
52 template <typename Xs, typename = void>
53 struct replace_impl : replace_impl<Xs, when<true>> { };
54
55 struct replace_t {
56 template <typename Xs, typename OldVal, typename NewVal>
57 constexpr auto operator()(Xs&& xs, OldVal&& oldval, NewVal&& newval) const;
58 };
59
60 BOOST_HANA_INLINE_VARIABLE constexpr replace_t replace{};
61#endif
62}} // end namespace boost::hana
63
64#endif // !BOOST_HANA_FWD_REPLACE_HPP
65

source code of boost/libs/hana/include/boost/hana/fwd/replace.hpp