merge(3p/immer): Subtree merge at 'ad3e3556d' as 'third_party/immer'

Change-Id: I9636a41ad44b4218293833fd3e9456d9b07c731b

third_party/immer/test/vector_transient/default.cpp

@@ -0,0 +1,15 @@
+//
+// immer: immutable data structures for C++
+// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente
+//
+// This software is distributed under the Boost Software License, Version 1.0.
+// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
+//
+
+#include <immer/vector.hpp>
+#include <immer/vector_transient.hpp>
+
+#define VECTOR_T ::immer::vector
+#define VECTOR_TRANSIENT_T ::immer::vector_transient
+
+#include "generic.ipp"