| // Copyright 2021 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/cxx17_backports.h" |
| |
| #include <array> |
| #include <memory> |
| #include <tuple> |
| #include <type_traits> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/test/gtest_util.h" |
| #include "testing/gmock/include/gmock/gmock.h" |
| #include "testing/gtest/include/gtest/gtest.h" |
| |
| namespace base { |
| namespace { |
| |
| TEST(Cxx17BackportTest, Size) { |
| { |
| std::vector<int> vector = {1, 2, 3, 4, 5}; |
| static_assert( |
| std::is_same<decltype(std::size(vector)), |
| decltype(vector.size())>::value, |
| "std::size(vector) should have the same type as vector.size()"); |
| EXPECT_EQ(vector.size(), std::size(vector)); |
| } |
| |
| { |
| std::string empty_str; |
| static_assert( |
| std::is_same<decltype(std::size(empty_str)), |
| decltype(empty_str.size())>::value, |
| "std::size(empty_str) should have the same type as empty_str.size()"); |
| EXPECT_EQ(0u, std::size(empty_str)); |
| } |
| |
| { |
| std::array<int, 4> array = {{1, 2, 3, 4}}; |
| static_assert( |
| std::is_same<decltype(std::size(array)), decltype(array.size())>::value, |
| "std::size(array) should have the same type as array.size()"); |
| static_assert(std::size(array) == array.size(), |
| "std::size(array) should be equal to array.size()"); |
| } |
| |
| { |
| int array[] = {1, 2, 3}; |
| static_assert(std::is_same<size_t, decltype(std::size(array))>::value, |
| "std::size(array) should be of type size_t"); |
| static_assert(3u == std::size(array), "std::size(array) should be 3"); |
| } |
| } |
| |
| TEST(Cxx17BackportTest, Empty) { |
| { |
| std::vector<int> vector; |
| static_assert( |
| std::is_same<decltype(std::empty(vector)), |
| decltype(vector.empty())>::value, |
| "std::empty(vector) should have the same type as vector.empty()"); |
| EXPECT_EQ(vector.empty(), std::empty(vector)); |
| } |
| |
| { |
| std::array<int, 4> array = {{1, 2, 3, 4}}; |
| static_assert( |
| std::is_same<decltype(std::empty(array)), |
| decltype(array.empty())>::value, |
| "std::empty(array) should have the same type as array.empty()"); |
| static_assert(std::empty(array) == array.empty(), |
| "std::empty(array) should be equal to array.empty()"); |
| } |
| |
| { |
| int array[] = {1, 2, 3}; |
| static_assert(std::is_same<bool, decltype(std::empty(array))>::value, |
| "std::empty(array) should be of type bool"); |
| static_assert(!std::empty(array), "std::empty(array) should be false"); |
| } |
| |
| { |
| constexpr std::initializer_list<int> il; |
| static_assert(std::is_same<bool, decltype(std::empty(il))>::value, |
| "std::empty(il) should be of type bool"); |
| static_assert(std::empty(il), "std::empty(il) should be true"); |
| } |
| } |
| |
| TEST(Cxx17BackportTest, Data) { |
| { |
| std::vector<int> vector = {1, 2, 3, 4, 5}; |
| static_assert( |
| std::is_same<decltype(std::data(vector)), |
| decltype(vector.data())>::value, |
| "std::data(vector) should have the same type as vector.data()"); |
| EXPECT_EQ(vector.data(), std::data(vector)); |
| } |
| |
| { |
| const std::string cstr = "const string"; |
| static_assert( |
| std::is_same<decltype(std::data(cstr)), decltype(cstr.data())>::value, |
| "std::data(cstr) should have the same type as cstr.data()"); |
| |
| EXPECT_EQ(cstr.data(), std::data(cstr)); |
| } |
| |
| { |
| std::string str = "mutable string"; |
| static_assert(std::is_same<decltype(std::data(str)), char*>::value, |
| "std::data(str) should be of type char*"); |
| EXPECT_EQ(str.data(), std::data(str)); |
| } |
| |
| { |
| std::string empty_str; |
| static_assert(std::is_same<decltype(std::data(empty_str)), char*>::value, |
| "std::data(empty_str) should be of type char*"); |
| EXPECT_EQ(empty_str.data(), std::data(empty_str)); |
| } |
| |
| { |
| std::array<int, 4> array = {{1, 2, 3, 4}}; |
| static_assert( |
| std::is_same<decltype(std::data(array)), decltype(array.data())>::value, |
| "std::data(array) should have the same type as array.data()"); |
| // std::array::data() is not constexpr prior to C++17, hence the runtime |
| // check. |
| EXPECT_EQ(array.data(), std::data(array)); |
| } |
| |
| { |
| constexpr int array[] = {1, 2, 3}; |
| static_assert(std::is_same<const int*, decltype(std::data(array))>::value, |
| "std::data(array) should be of type const int*"); |
| static_assert(array == std::data(array), |
| "std::data(array) should be array"); |
| } |
| |
| { |
| constexpr std::initializer_list<int> il; |
| static_assert( |
| std::is_same<decltype(il.begin()), decltype(std::data(il))>::value, |
| "std::data(il) should have the same type as il.begin()"); |
| static_assert(il.begin() == std::data(il), |
| "std::data(il) should be equal to il.begin()"); |
| } |
| } |
| |
| struct OneType { |
| int some_int; |
| }; |
| |
| bool operator<(const OneType& lhs, const OneType& rhs) { |
| return lhs.some_int < rhs.some_int; |
| } |
| |
| bool operator==(const OneType& lhs, const OneType& rhs) { |
| return lhs.some_int == rhs.some_int; |
| } |
| |
| struct AnotherType { |
| int some_other_int; |
| }; |
| |
| bool operator==(const AnotherType& lhs, const AnotherType& rhs) { |
| return lhs.some_other_int == rhs.some_other_int; |
| } |
| |
| TEST(Cxx17BackportTest, Clamp) { |
| EXPECT_EQ(0, base::clamp(-5, 0, 10)); |
| EXPECT_EQ(0, base::clamp(0, 0, 10)); |
| EXPECT_EQ(3, base::clamp(3, 0, 10)); |
| EXPECT_EQ(10, base::clamp(10, 0, 10)); |
| EXPECT_EQ(10, base::clamp(15, 0, 10)); |
| |
| EXPECT_EQ(0.0, base::clamp(-5.0, 0.0, 10.0)); |
| EXPECT_EQ(0.0, base::clamp(0.0, 0.0, 10.0)); |
| EXPECT_EQ(3.0, base::clamp(3.0, 0.0, 10.0)); |
| EXPECT_EQ(10.0, base::clamp(10.0, 0.0, 10.0)); |
| EXPECT_EQ(10.0, base::clamp(15.0, 0.0, 10.0)); |
| |
| EXPECT_EQ(0, base::clamp(-5, 0, 0)); |
| EXPECT_EQ(0, base::clamp(0, 0, 0)); |
| EXPECT_EQ(0, base::clamp(3, 0, 0)); |
| |
| OneType one_type_neg5{-5}; |
| OneType one_type_0{0}; |
| OneType one_type_3{3}; |
| OneType one_type_10{10}; |
| OneType one_type_15{15}; |
| |
| EXPECT_EQ(one_type_0, base::clamp(one_type_neg5, one_type_0, one_type_10)); |
| EXPECT_EQ(one_type_0, base::clamp(one_type_0, one_type_0, one_type_10)); |
| EXPECT_EQ(one_type_3, base::clamp(one_type_3, one_type_0, one_type_10)); |
| EXPECT_EQ(one_type_10, base::clamp(one_type_10, one_type_0, one_type_10)); |
| EXPECT_EQ(one_type_10, base::clamp(one_type_15, one_type_0, one_type_10)); |
| |
| AnotherType another_type_neg5{-5}; |
| AnotherType another_type_0{0}; |
| AnotherType another_type_3{3}; |
| AnotherType another_type_10{10}; |
| AnotherType another_type_15{15}; |
| |
| auto compare_another_type = [](const auto& lhs, const auto& rhs) { |
| return lhs.some_other_int < rhs.some_other_int; |
| }; |
| |
| EXPECT_EQ(another_type_0, base::clamp(another_type_neg5, another_type_0, |
| another_type_10, compare_another_type)); |
| EXPECT_EQ(another_type_0, base::clamp(another_type_0, another_type_0, |
| another_type_10, compare_another_type)); |
| EXPECT_EQ(another_type_3, base::clamp(another_type_3, another_type_0, |
| another_type_10, compare_another_type)); |
| EXPECT_EQ(another_type_10, |
| base::clamp(another_type_10, another_type_0, another_type_10, |
| compare_another_type)); |
| EXPECT_EQ(another_type_10, |
| base::clamp(another_type_15, another_type_0, another_type_10, |
| compare_another_type)); |
| |
| EXPECT_CHECK_DEATH(base::clamp(3, 10, 0)); |
| EXPECT_CHECK_DEATH(base::clamp(3.0, 10.0, 0.0)); |
| EXPECT_CHECK_DEATH(base::clamp(one_type_3, one_type_10, one_type_0)); |
| EXPECT_CHECK_DEATH(base::clamp(another_type_3, another_type_10, |
| another_type_0, compare_another_type)); |
| } |
| |
| constexpr int Subtract(int a, int b) { |
| return a - b; |
| } |
| |
| int SubtractUnique(std::unique_ptr<int> a, std::unique_ptr<int> b) { |
| return *a - *b; |
| } |
| |
| TEST(Cxx17BackportTest, Apply) { |
| // Function |
| constexpr std::tuple<int, int> tuple1(3, 2); |
| static_assert(base::apply(&Subtract, tuple1) == 1, |
| "base::apply() can invoke functions as constexpr"); |
| |
| // Function with move-only types |
| std::tuple<std::unique_ptr<int>, std::unique_ptr<int>> tuple2( |
| std::make_unique<int>(3), std::make_unique<int>(2)); |
| EXPECT_EQ(1, base::apply(&SubtractUnique, std::move(tuple2))); |
| |
| // Lambda |
| const auto subtract_lambda = [](int a, int b) { return a - b; }; |
| EXPECT_EQ(1, base::apply(subtract_lambda, tuple1)); |
| |
| // Member function |
| class Foo { |
| public: |
| constexpr Foo(int a) : a_(a) {} |
| |
| constexpr int Bar(int b) const { return a_ - b; } |
| |
| private: |
| int a_; |
| }; |
| static constexpr Foo f(3); |
| constexpr std::tuple<const Foo*, int> tuple3(&f, 2); |
| static_assert(base::apply(&Foo::Bar, tuple3) == 1, |
| "base::apply() can invoke member functions as constexpr"); |
| } |
| |
| } // namespace |
| } // namespace base |