add flatbuffers

commit 6da1cf79d90eb242e7da5318241d42279a3df3ba
Author: Max Burke <max@urbanlogiq.com>
Date:   Sun Jan 19 14:47:28 2020 -0800

    [rust] Add use declarations to Rust-generated bindings for imported FB definitions (#5645)

    * Bugfix for Rust generation of union fields named with language keywords

flatbuffers/tests/cpp17/test_cpp17.cpp

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2014 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// This is a sandbox for modeling C++17 code generator.
+// C++17 code generator: "flatc --cpp_std c++17".
+// Warning:
+// This is an experimental feature and could change at any time.
+
+#include "flatbuffers/flatbuffers.h"
+#include "flatbuffers/flexbuffers.h"
+#include "flatbuffers/idl.h"
+#include "flatbuffers/minireflect.h"
+#include "flatbuffers/registry.h"
+#include "flatbuffers/util.h"
+#include "test_assert.h"
+
+// Embed generated code into an isolated namespace.
+namespace cpp17 {
+#include "generated_cpp17/monster_test_generated.h"
+}  // namespace cpp17
+
+namespace cpp11 {
+#include "../monster_test_generated.h"
+}  // namespace cpp11
+
+void CreateTableByTypeTest() {
+  flatbuffers::FlatBufferBuilder builder;
+
+  // We will create an object of this type using only the type.
+  using type_to_create_t = cpp17::MyGame::Example::Stat;
+
+  [&builder] {
+    auto id_str = builder.CreateString("my_id");
+    auto table = type_to_create_t::Traits::Create(builder, id_str, 42, 7);
+    // Be sure that the correct return type was inferred.
+    static_assert(
+        std::is_same_v<decltype(table), flatbuffers::Offset<type_to_create_t>>);
+    builder.Finish(table);
+  }();
+
+  // Access it.
+  auto stat =
+      flatbuffers::GetRoot<type_to_create_t>(builder.GetBufferPointer());
+  TEST_EQ_STR(stat->id()->c_str(), "my_id");
+  TEST_EQ(stat->val(), 42);
+  TEST_EQ(stat->count(), 7);
+}
+
+int FlatBufferCpp17Tests() {
+  CreateTableByTypeTest();
+  return 0;
+}
+
+int main(int /*argc*/, const char * /*argv*/[]) {
+  InitTestEngine();
+
+  FlatBufferCpp17Tests();
+
+  if (!testing_fails) {
+    TEST_OUTPUT_LINE("C++17: ALL TESTS PASSED");
+  } else {
+    TEST_OUTPUT_LINE("C++17: %d FAILED TESTS", testing_fails);
+  }
+  return CloseTestEngine();
+}