70 lines
2.3 KiB
C++
70 lines
2.3 KiB
C++
|
/*!
|
||
|
|
@file
|
||
|
|
Forward declares `boost::hana::adjust_if`.
|
||
|
|
|
||
|
|
@copyright Louis Dionne 2013-2016
|
||
|
|
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
|