merge(3p/immer): Subtree merge at 'ad3e3556d' as 'third_party/immer' r/1299

Change-Id: I9636a41ad44b4218293833fd3e9456d9b07c731b

1 files changed, 22 insertions, 0 deletions

diff --git a/third_party/immer/example/set/intro.cpp b/third_party/immer/example/set/intro.cpp
new file mode 100644
index 000000000000..be932ce65475
--- /dev/null
+++ b/third_party/immer/example/set/intro.cpp
@@ -0,0 +1,22 @@
+//
+// 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:intro/start
+#include <immer/set.hpp>
+int main()
+{
+    const auto v0 = immer::set<int>{};
+    const auto v1 = v0.insert(42);
+    assert(v0.count(42) == 0);
+    assert(v1.count(42) == 1);
+
+    const auto v2 = v1.erase(42);
+    assert(v1.count(42) == 1);
+    assert(v2.count(42) == 0);
+}
+// include:intro/end