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a5d9d0f7d3
* Include flattests_cpp17 in unit tests when C++17 build is enabled.
* [C++17] Generate generic table factory function.
1. For each table, generate a convenient free-standing factory
function that allows creating the table in a generic way by
specifying only the type. This is the first change in a series
of changes to make Flatbuffers generated C++ code more friendly
to code bases that make use of C++ template metaprogramming
techniques to manage the serialization process. Example:
Before :(
// The name of the Flatbuffers type (and namespace) must
// be hard-coded when writing the factory function.
auto monster = MyGame::Example::CreateMonster(fbb, ...);
After :)
using type_to_create = MyGame::Example::Monster;
// No namespace needed on CreateByTagType.
auto monster = CreateByTagType((type_to_create*)nullptr,
fbb, ...);
This feature requires building with C++14 or greater, and thus
it is guarded behind --cpp-std >= c++17 in the flatbuffers C++
generator.
2. Fix a CMake bug to include C++17 unit tests in test suite.
* [C++17] Replace standalone variadic factory function with type_traits.
Add a `type_traits` to each table class. This `type_traits` can be
populated with various compile-time info about the table. Initially,
we have the Create* function and type, but is extensible in the future.
* Remove empty line and fix stale comments.
* Rename type_traits to Traits and move fwd declaration.
* Fix parameter evaluation order issue and use lambda for scope.
79 lines
2.3 KiB
C++
79 lines
2.3 KiB
C++
/*
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* Copyright 2014 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// This is a sandbox for modeling C++17 code generator.
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// C++17 code generator: "flatc --cpp_std c++17".
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// Warning:
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// This is an experimental feature and could change at any time.
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#include "flatbuffers/flatbuffers.h"
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#include "flatbuffers/flexbuffers.h"
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#include "flatbuffers/idl.h"
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#include "flatbuffers/minireflect.h"
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#include "flatbuffers/registry.h"
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#include "flatbuffers/util.h"
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#include "test_assert.h"
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// Embed generated code into an isolated namespace.
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namespace cpp17 {
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#include "generated_cpp17/monster_test_generated.h"
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} // namespace cpp17
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namespace cpp11 {
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#include "../monster_test_generated.h"
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} // namespace cpp11
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void CreateTableByTypeTest() {
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flatbuffers::FlatBufferBuilder builder;
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// We will create an object of this type using only the type.
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using type_to_create_t = cpp17::MyGame::Example::Stat;
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[&builder] {
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auto id_str = builder.CreateString("my_id");
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auto table = type_to_create_t::Traits::Create(builder, id_str, 42, 7);
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// Be sure that the correct return type was inferred.
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static_assert(
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std::is_same_v<decltype(table), flatbuffers::Offset<type_to_create_t>>);
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builder.Finish(table);
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}();
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// Access it.
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auto stat =
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flatbuffers::GetRoot<type_to_create_t>(builder.GetBufferPointer());
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TEST_EQ_STR(stat->id()->c_str(), "my_id");
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TEST_EQ(stat->val(), 42);
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TEST_EQ(stat->count(), 7);
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}
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int FlatBufferCpp17Tests() {
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CreateTableByTypeTest();
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return 0;
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}
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int main(int /*argc*/, const char * /*argv*/[]) {
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InitTestEngine();
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FlatBufferCpp17Tests();
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if (!testing_fails) {
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TEST_OUTPUT_LINE("C++17: ALL TESTS PASSED");
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} else {
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TEST_OUTPUT_LINE("C++17: %d FAILED TESTS", testing_fails);
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}
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return CloseTestEngine();
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}
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