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// Copyright Louis Dionne 2013-2022
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <boost/hana/bool.hpp>
#include <boost/hana/eval_if.hpp>
#include <boost/hana/fwd/not.hpp>
#include <boost/hana/fwd/while.hpp>
#include <boost/hana/if.hpp>
namespace hana = boost::hana;
// This test makes sure that if_ can be used with non-copyable branches.
template <bool Value>
struct Boolean { };
namespace boost { namespace hana {
template <bool Value>
struct while_impl<Boolean<Value>> {
// Not implemented
};
template <bool Value>
struct not_impl<Boolean<Value>> {
// Not implemented
};
template <bool Value>
struct eval_if_impl<Boolean<Value>> {
template <typename Cond, typename Then, typename Else>
static constexpr decltype(auto) apply(Cond const&, Then&& t, Else&& e) {
return hana::eval_if(hana::bool_c<Value>, static_cast<Then&&>(t),
static_cast<Else&&>(e));
}
};
}}
template <int v>
struct NonCopyable {
static constexpr int value = v;
NonCopyable() = default;
NonCopyable(NonCopyable const&) = delete;
NonCopyable(NonCopyable&&) = default;
NonCopyable& operator=(NonCopyable const&) = delete;
NonCopyable& operator=(NonCopyable&&) = default;
};
static_assert(hana::if_(Boolean<true>{}, NonCopyable<3>{}, NonCopyable<4>{}).value == 3, "");
static_assert(hana::if_(Boolean<false>{}, NonCopyable<3>{}, NonCopyable<4>{}).value == 4, "");
int main() { }
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