cxx/test/utilities/memory/util.smartptr/util.smartptr.shared.atomic/atomic_exchange_explicit.pass.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.
//
//===----------------------------------------------------------------------===//
//
// This test uses new symbols that were not defined in the libc++ shipped on
// darwin11 and darwin12:
// XFAIL: with_system_lib=x86_64-apple-darwin11
// XFAIL: with_system_lib=x86_64-apple-darwin12

// <memory>

// shared_ptr

// template <class T>
// shared_ptr<T>
// atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r)

#include <memory>
#include <cassert>

int main()
{
#if __has_feature(cxx_atomic)
    {
        std::shared_ptr<int> p(new int(4));
        std::shared_ptr<int> r(new int(3));
        r = std::atomic_exchange_explicit(&p, r, std::memory_order_seq_cst);
        assert(*p == 3);
        assert(*r == 4);
    }
#endif
}