1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
/*!
@file
Forward declares `boost::hana::adjust_if`.
@copyright Louis Dionne 2013-2017
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_ADJUST_IF_HPP
#define BOOST_HANA_FWD_ADJUST_IF_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/core/when.hpp>
BOOST_HANA_NAMESPACE_BEGIN
//! Apply a function on all the elements of a structure satisfying a predicate.
//! @ingroup group-Functor
//!
//! Given a Functor, a predicate `pred` and a function `f`, `adjust_if`
//! will _adjust_ the elements of the Functor that satisfy the predicate
//! with the function `f`. In other words, `adjust_if` will return a new
//! Functor equal to the original one, except that the elements satisfying
//! the predicate will be transformed with the given function. Elements
//! for which the predicate is not satisfied are left untouched, and they
//! are kept as-is in the resulting Functor.
//!
//!
//! Signature
//! ---------
//! Given a `Functor` `F` and a `Logical` `Bool`, the signature is
//! \f$
//! \mathtt{adjust_if} : F(T) \times (T \to Bool) \times (T \to T) \to F(T)
//! \f$
//!
//! @param xs
//! The structure to adjust with `f`.
//!
//! @param pred
//! A function called as `pred(x)` for each element of the Functor,
//! and returning whether `f` should be applied on that element.
//!
//! @param f
//! A function called as `f(x)` on the element(s) of the Functor that
//! satisfy the predicate.
//!
//!
//! Example
//! -------
//! @include example/adjust_if.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
constexpr auto adjust_if = [](auto&& xs, auto const& pred, auto const& f) {
return tag-dispatched;
};
#else
template <typename Xs, typename = void>
struct adjust_if_impl : adjust_if_impl<Xs, when<true>> { };
struct adjust_if_t {
template <typename Xs, typename Pred, typename F>
constexpr auto operator()(Xs&& xs, Pred const& pred, F const& f) const;
};
constexpr adjust_if_t adjust_if{};
#endif
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_FWD_ADJUST_IF_HPP
|
