1 files changed, 46 insertions, 0 deletions
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp
new file mode 100644
index 0000000000000..89c28e6be73c9
--- /dev/null
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp
@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
+
+// <mutex>
+
+// template <class Mutex> class unique_lock;
+
+// mutex_type* release() noexcept;
+
+#include <mutex>
+#include <cassert>
+
+struct mutex
+{
+    static int lock_count;
+    static int unlock_count;
+    void lock() {++lock_count;}
+    void unlock() {++unlock_count;}
+};
+
+int mutex::lock_count = 0;
+int mutex::unlock_count = 0;
+
+mutex m;
+
+int main()
+{
+    std::unique_lock<mutex> lk(m);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == true);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+    assert(lk.release() == &m);
+    assert(lk.mutex() == nullptr);
+    assert(lk.owns_lock() == false);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+}