// 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) #include #include #include #include namespace hana = boost::hana; template T const& cref(T& t) { return t; } // a non-movable, non-copyable type template struct RefOnly { RefOnly() = default; RefOnly(RefOnly const&) = delete; RefOnly(RefOnly&&) = delete; }; int main() { // This test makes sure that we return the proper reference types from // `first` and `second`. std::pair, RefOnly<1>> p; { RefOnly<0>&& r1 = hana::first(std::move(p)); RefOnly<0>& r2 = hana::first(p); RefOnly<0> const& r3 = hana::first(cref(p)); (void)r1; (void)r2; (void)r3; } { RefOnly<1>&& r1 = hana::second(std::move(p)); RefOnly<1>& r2 = hana::second(p); RefOnly<1> const& r3 = hana::second(cref(p)); (void)r1; (void)r2; (void)r3; } }