1/*!
2@file
3Forward declares `boost::hana::transform`.
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_TRANSFORM_HPP
11#define BOOST_HANA_FWD_TRANSFORM_HPP
12
13#include <boost/hana/config.hpp>
14#include <boost/hana/core/when.hpp>
15
16
17namespace boost { namespace hana {
18 //! Map a function over a `Functor`.
19 //! @ingroup group-Functor
20 //!
21 //!
22 //! Signature
23 //! ---------
24 //! Given `F` a Functor, the signature is
25 //! \f$
26 //! \mathtt{transform} : F(T) \times (T \to U) \to F(U)
27 //! \f$
28 //!
29 //! @param xs
30 //! The structure to map `f` over.
31 //!
32 //! @param f
33 //! A function called as `f(x)` on element(s) `x` of the structure,
34 //! and returning a new value to replace `x` in the structure.
35 //!
36 //!
37 //! Example
38 //! -------
39 //! @include example/transform.cpp
40#ifdef BOOST_HANA_DOXYGEN_INVOKED
41 constexpr auto transform = [](auto&& xs, auto&& f) {
42 return tag-dispatched;
43 };
44#else
45 template <typename Xs, typename = void>
46 struct transform_impl : transform_impl<Xs, when<true>> { };
47
48 struct transform_t {
49 template <typename Xs, typename F>
50 constexpr auto operator()(Xs&& xs, F&& f) const;
51 };
52
53 BOOST_HANA_INLINE_VARIABLE constexpr transform_t transform{};
54#endif
55}} // end namespace boost::hana
56
57#endif // !BOOST_HANA_FWD_TRANSFORM_HPP
58

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