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// Copyright 2023 The Abseil Authors
//
// 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
//
// https://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.
#include "absl/utility/internal/if_constexpr.h"
#include <utility>
#include "gtest/gtest.h"
namespace {
struct Empty {};
struct HasFoo {
int foo() const { return 1; }
};
TEST(IfConstexpr, Basic) {
int i = 0;
absl::utility_internal::IfConstexpr<false>(
[&](const auto& t) { i = t.foo(); }, Empty{});
EXPECT_EQ(i, 0);
absl::utility_internal::IfConstexpr<false>(
[&](const auto& t) { i = t.foo(); }, HasFoo{});
EXPECT_EQ(i, 0);
absl::utility_internal::IfConstexpr<true>(
[&](const auto& t) { i = t.foo(); }, HasFoo{});
EXPECT_EQ(i, 1);
}
TEST(IfConstexprElse, Basic) {
EXPECT_EQ(absl::utility_internal::IfConstexprElse<false>(
[&](const auto& t) { return t.foo(); }, [&](const auto&) { return 2; },
Empty{}), 2);
EXPECT_EQ(absl::utility_internal::IfConstexprElse<false>(
[&](const auto& t) { return t.foo(); }, [&](const auto&) { return 2; },
HasFoo{}), 2);
EXPECT_EQ(absl::utility_internal::IfConstexprElse<true>(
[&](const auto& t) { return t.foo(); }, [&](const auto&) { return 2; },
HasFoo{}), 1);
}
struct HasFooRValue {
int foo() && { return 1; }
};
struct RValueFunc {
void operator()(HasFooRValue&& t) && { *i = std::move(t).foo(); }
int* i = nullptr;
};
TEST(IfConstexpr, RValues) {
int i = 0;
RValueFunc func = {&i};
absl::utility_internal::IfConstexpr<false>(
std::move(func), HasFooRValue{});
EXPECT_EQ(i, 0);
func = RValueFunc{&i};
absl::utility_internal::IfConstexpr<true>(
std::move(func), HasFooRValue{});
EXPECT_EQ(i, 1);
}
} // namespace
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