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/**
* Copyright (C) 2022-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#include "mongo/util/optional_util.h"
#include <boost/optional.hpp>
#include <optional>
#include <sstream>
#include <string>
#include "mongo/unittest/unittest.h"
namespace mongo {
namespace {
// Confine the nolint escaping to one place.
template <typename T>
using StdOptional = std::optional<T>; // NOLINT
auto&& StdNullopt = std::nullopt; // NOLINT
template <template <typename> class O, typename T, typename... As>
O<T> mkOpt(As&&... as) {
return O<T>(std::forward<As>(as)...);
}
/** Deduce `T`, and wrap `v` in an `O<T>`, and do this `N` times. */
template <template <typename> class O, size_t N, typename T>
auto optWrap(T v) {
if constexpr (N == 0)
return v;
else
return optWrap<O, N - 1>(O<T>{std::move(v)});
}
template <typename T>
std::string str(const T& v) {
std::ostringstream os;
os << optional_io::Extension(v);
return os.str();
}
MONGO_STATIC_ASSERT(isBoostOptional<boost::optional<int>>);
MONGO_STATIC_ASSERT(!isBoostOptional<int>);
MONGO_STATIC_ASSERT(!optional_io::canStream<StdOptional<int>>);
MONGO_STATIC_ASSERT(optional_io::canStreamWithExtension<StdOptional<int>>);
// boost::optional provides a SFINAE-hostile operator<<
MONGO_STATIC_ASSERT(optional_io::canStream<boost::optional<int>>);
MONGO_STATIC_ASSERT(optional_io::canStreamWithExtension<boost::optional<int>>);
TEST(OptionalUtil, ExtendedFormat) {
ASSERT_EQ(str(123), "123");
ASSERT_EQ(str(boost::none), "--");
ASSERT_EQ(str(mkOpt<boost::optional, int>(123)), " 123");
ASSERT_EQ(str(mkOpt<boost::optional, int>()), "--");
ASSERT_EQ(str(StdNullopt), "--");
ASSERT_EQ(str(mkOpt<StdOptional, int>(123)), " 123");
ASSERT_EQ(str(mkOpt<StdOptional, int>()), "--");
ASSERT_EQ(str(optWrap<boost::optional, 0>(123)), "123");
ASSERT_EQ(str(optWrap<boost::optional, 1>(123)), " 123");
ASSERT_EQ(str(optWrap<boost::optional, 2>(123)), " 123");
ASSERT_EQ(str(optWrap<StdOptional, 0>(123)), "123");
ASSERT_EQ(str(optWrap<StdOptional, 1>(123)), " 123");
ASSERT_EQ(str(optWrap<StdOptional, 2>(123)), " 123");
}
} // namespace
} // namespace mongo
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