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/*!
@file
Defines `boost::hana::replace`.
@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_REPLACE_HPP
#define BOOST_HANA_REPLACE_HPP
#include <boost/hana/fwd/replace.hpp>
#include <boost/hana/concept/functor.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/core/dispatch.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/replace_if.hpp>
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template <typename Xs, typename OldVal, typename NewVal>
constexpr auto replace_t::operator()(Xs&& xs, OldVal&& oldval, NewVal&& newval) const {
using S = typename hana::tag_of<Xs>::type;
using Replace = BOOST_HANA_DISPATCH_IF(replace_impl<S>,
hana::Functor<S>::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Functor<S>::value,
"hana::replace(xs, oldval, newval) requires 'xs' to be a Functor");
#endif
return Replace::apply(static_cast<Xs&&>(xs),
static_cast<OldVal&&>(oldval),
static_cast<NewVal&&>(newval));
}
//! @endcond
template <typename Fun, bool condition>
struct replace_impl<Fun, when<condition>> : default_ {
template <typename Xs, typename OldVal, typename NewVal>
static constexpr decltype(auto)
apply(Xs&& xs, OldVal&& oldval, NewVal&& newval) {
return hana::replace_if(
static_cast<Xs&&>(xs),
hana::equal.to(static_cast<OldVal&&>(oldval)),
static_cast<NewVal&&>(newval)
);
}
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_REPLACE_HPP
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