libcxx/test/std/utilities/tuple/tuple.tuple/tuple.elem/get_const_rv.fail.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <tuple>

// template <class... Types> class tuple;

// template <size_t I, class... Types>
//   const typename tuple_element<I, tuple<Types...> >::type&&
//   get(const tuple<Types...>&& t);

// UNSUPPORTED: c++98, c++03

#include <tuple>

template <class T> void cref(T const&) {};
template <class T> void cref(T const&&) = delete;

std::tuple<int> const tup4() { return std::make_tuple(4); }

int main()
{
    // LWG2485: tuple should not open a hole in the type system, get() should
    // imitate [expr.ref]'s rules for accessing data members
    {
        cref(std::get<0>(tup4()));  // expected-error {{call to deleted function 'cref'}}
    }
}