xref: /llvm-project/libcxx/test/support/test_comparisons.h (revision f8b5ac34adb9d6e60202d8cc92d9c3cd02806c66)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //  A set of routines for testing the comparison operators of a type
9 //
10 //      FooOrder<expected-ordering>  All seven comparison operators, requires C++20 or newer.
11 //      FooComparison                All six pre-C++20 comparison operators
12 //      FooEquality                  Equality operators operator== and operator!=
13 //
14 //      AssertXAreNoexcept           static_asserts that the operations are all noexcept.
15 //      AssertXReturnBool            static_asserts that the operations return bool.
16 //      AssertOrderReturn            static_asserts that the pre-C++20 comparison operations
17 //                                   return bool and operator<=> returns the proper type.
18 //      AssertXConvertibleToBool     static_asserts that the operations return something convertible to bool.
19 //      testXValues                  returns the result of the comparison of all operations.
20 //
21 //      AssertOrderConvertibleToBool doesn't exist yet. It will be implemented when needed.
22 
23 #ifndef TEST_COMPARISONS_H
24 #define TEST_COMPARISONS_H
25 
26 #include <cassert>
27 #include <compare>
28 #include <concepts>
29 #include <limits>
30 #include <type_traits>
31 #include <utility>
32 
33 #include "test_macros.h"
34 
35 // Test the consistency of the six basic comparison operators for values that are ordered or unordered.
36 template <class T, class U = T>
37 TEST_NODISCARD TEST_CONSTEXPR_CXX14 bool
38 testComparisonsComplete(const T& t1, const U& t2, bool isEqual, bool isLess, bool isGreater) {
39     assert(((isEqual ? 1 : 0) + (isLess ? 1 : 0) + (isGreater ? 1 : 0) <= 1) &&
40            "at most one of isEqual, isLess, and isGreater can be true");
41     if (isEqual) {
42         if (!(t1 == t2)) return false;
43         if (!(t2 == t1)) return false;
44         if ( (t1 != t2)) return false;
45         if ( (t2 != t1)) return false;
46         if ( (t1  < t2)) return false;
47         if ( (t2  < t1)) return false;
48         if (!(t1 <= t2)) return false;
49         if (!(t2 <= t1)) return false;
50         if ( (t1  > t2)) return false;
51         if ( (t2  > t1)) return false;
52         if (!(t1 >= t2)) return false;
53         if (!(t2 >= t1)) return false;
54     } else if (isLess) {
55         if ( (t1 == t2)) return false;
56         if ( (t2 == t1)) return false;
57         if (!(t1 != t2)) return false;
58         if (!(t2 != t1)) return false;
59         if (!(t1  < t2)) return false;
60         if ( (t2  < t1)) return false;
61         if (!(t1 <= t2)) return false;
62         if ( (t2 <= t1)) return false;
63         if ( (t1  > t2)) return false;
64         if (!(t2  > t1)) return false;
65         if ( (t1 >= t2)) return false;
66         if (!(t2 >= t1)) return false;
67     } else if (isGreater) {
68         if ( (t1 == t2)) return false;
69         if ( (t2 == t1)) return false;
70         if (!(t1 != t2)) return false;
71         if (!(t2 != t1)) return false;
72         if ( (t1  < t2)) return false;
73         if (!(t2  < t1)) return false;
74         if ( (t1 <= t2)) return false;
75         if (!(t2 <= t1)) return false;
76         if (!(t1  > t2)) return false;
77         if ( (t2  > t1)) return false;
78         if (!(t1 >= t2)) return false;
79         if ( (t2 >= t1)) return false;
80     } else { // unordered
81         if ( (t1 == t2)) return false;
82         if ( (t2 == t1)) return false;
83         if (!(t1 != t2)) return false;
84         if (!(t2 != t1)) return false;
85         if ( (t1  < t2)) return false;
86         if ( (t2  < t1)) return false;
87         if ( (t1 <= t2)) return false;
88         if ( (t2 <= t1)) return false;
89         if ( (t1  > t2)) return false;
90         if ( (t2  > t1)) return false;
91         if ( (t1 >= t2)) return false;
92         if ( (t2 >= t1)) return false;
93     }
94 
95     return true;
96 }
97 
98 // Test the six basic comparison operators for ordered values.
99 template <class T, class U = T>
100 TEST_NODISCARD TEST_CONSTEXPR_CXX14 bool testComparisons(const T& t1, const U& t2, bool isEqual, bool isLess) {
101     assert(!(isEqual && isLess) && "isEqual and isLess cannot be both true");
102     bool isGreater = !isEqual && !isLess;
103     return testComparisonsComplete(t1, t2, isEqual, isLess, isGreater);
104 }
105 
106 //  Easy call when you can init from something already comparable.
107 template <class T, class Param>
108 TEST_NODISCARD TEST_CONSTEXPR_CXX14 bool testComparisonsValues(Param val1, Param val2)
109 {
110     const bool isEqual   = val1 == val2;
111     const bool isLess    = val1 <  val2;
112     const bool isGreater = val1  > val2;
113 
114     return testComparisonsComplete(T(val1), T(val2), isEqual, isLess, isGreater);
115 }
116 
117 template <class T, class U = T>
118 TEST_CONSTEXPR_CXX14 void AssertComparisonsAreNoexcept() {
119     ASSERT_NOEXCEPT(std::declval<const T&>() == std::declval<const U&>());
120     ASSERT_NOEXCEPT(std::declval<const T&>() != std::declval<const U&>());
121     ASSERT_NOEXCEPT(std::declval<const T&>() <  std::declval<const U&>());
122     ASSERT_NOEXCEPT(std::declval<const T&>() <= std::declval<const U&>());
123     ASSERT_NOEXCEPT(std::declval<const T&>() >  std::declval<const U&>());
124     ASSERT_NOEXCEPT(std::declval<const T&>() >= std::declval<const U&>());
125 }
126 
127 template <class T, class U = T>
128 TEST_CONSTEXPR_CXX14 void AssertComparisonsReturnBool() {
129     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() == std::declval<const U&>()), bool);
130     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() != std::declval<const U&>()), bool);
131     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() <  std::declval<const U&>()), bool);
132     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() <= std::declval<const U&>()), bool);
133     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() >  std::declval<const U&>()), bool);
134     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() >= std::declval<const U&>()), bool);
135 }
136 
137 template <class T, class U = T>
138 void AssertComparisonsConvertibleToBool()
139 {
140     static_assert((std::is_convertible<decltype(std::declval<const T&>() == std::declval<const U&>()), bool>::value), "");
141     static_assert((std::is_convertible<decltype(std::declval<const T&>() != std::declval<const U&>()), bool>::value), "");
142     static_assert((std::is_convertible<decltype(std::declval<const T&>() <  std::declval<const U&>()), bool>::value), "");
143     static_assert((std::is_convertible<decltype(std::declval<const T&>() <= std::declval<const U&>()), bool>::value), "");
144     static_assert((std::is_convertible<decltype(std::declval<const T&>() >  std::declval<const U&>()), bool>::value), "");
145     static_assert((std::is_convertible<decltype(std::declval<const T&>() >= std::declval<const U&>()), bool>::value), "");
146 }
147 
148 #if TEST_STD_VER > 17
149 template <class T, class U = T>
150 constexpr void AssertOrderAreNoexcept() {
151     AssertComparisonsAreNoexcept<T, U>();
152     ASSERT_NOEXCEPT(std::declval<const T&>() <=> std::declval<const U&>());
153 }
154 
155 template <class Order, class T, class U = T>
156 constexpr void AssertOrderReturn() {
157     AssertComparisonsReturnBool<T, U>();
158     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() <=> std::declval<const U&>()), Order);
159 }
160 
161 template <class Order, class T, class U = T>
162 TEST_NODISCARD constexpr bool testOrder(const T& t1, const U& t2, Order order) {
163     bool equal   = order == Order::equivalent;
164     bool less    = order == Order::less;
165     bool greater = order == Order::greater;
166 
167     return (t1 <=> t2 == order) && testComparisonsComplete(t1, t2, equal, less, greater);
168 }
169 
170 template <class T, class Param>
171 TEST_NODISCARD constexpr bool testOrderValues(Param val1, Param val2) {
172   return testOrder(T(val1), T(val2), val1 <=> val2);
173 }
174 
175 #endif
176 
177 //  Test all two comparison operations for sanity
178 template <class T, class U = T>
179 TEST_NODISCARD TEST_CONSTEXPR_CXX14 bool testEquality(const T& t1, const U& t2, bool isEqual)
180 {
181     if (isEqual)
182         {
183         if (!(t1 == t2)) return false;
184         if (!(t2 == t1)) return false;
185         if ( (t1 != t2)) return false;
186         if ( (t2 != t1)) return false;
187         }
188     else /* not equal */
189         {
190         if ( (t1 == t2)) return false;
191         if ( (t2 == t1)) return false;
192         if (!(t1 != t2)) return false;
193         if (!(t2 != t1)) return false;
194         }
195 
196     return true;
197 }
198 
199 //  Easy call when you can init from something already comparable.
200 template <class T, class Param>
201 TEST_NODISCARD TEST_CONSTEXPR_CXX14 bool testEqualityValues(Param val1, Param val2)
202 {
203     const bool isEqual = val1 == val2;
204 
205     return testEquality(T(val1), T(val2), isEqual);
206 }
207 
208 template <class T, class U = T>
209 void AssertEqualityAreNoexcept()
210 {
211     ASSERT_NOEXCEPT(std::declval<const T&>() == std::declval<const U&>());
212     ASSERT_NOEXCEPT(std::declval<const T&>() != std::declval<const U&>());
213 }
214 
215 template <class T, class U = T>
216 void AssertEqualityReturnBool()
217 {
218     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() == std::declval<const U&>()), bool);
219     ASSERT_SAME_TYPE(decltype(std::declval<const T&>() != std::declval<const U&>()), bool);
220 }
221 
222 
223 template <class T, class U = T>
224 void AssertEqualityConvertibleToBool()
225 {
226     static_assert((std::is_convertible<decltype(std::declval<const T&>() == std::declval<const U&>()), bool>::value), "");
227     static_assert((std::is_convertible<decltype(std::declval<const T&>() != std::declval<const U&>()), bool>::value), "");
228 }
229 
230 struct LessAndEqComp {
231   int value;
232 
233   TEST_CONSTEXPR_CXX14 LessAndEqComp(int v) : value(v) {}
234 
235   friend TEST_CONSTEXPR_CXX14 bool operator<(const LessAndEqComp& lhs, const LessAndEqComp& rhs) {
236     return lhs.value < rhs.value;
237   }
238 
239   friend TEST_CONSTEXPR_CXX14 bool operator==(const LessAndEqComp& lhs, const LessAndEqComp& rhs) {
240     return lhs.value == rhs.value;
241   }
242 };
243 
244 #if TEST_STD_VER >= 20
245 
246 struct StrongOrder {
247   int value;
248   constexpr StrongOrder(int v) : value(v) {}
249   friend std::strong_ordering operator<=>(StrongOrder, StrongOrder) = default;
250 };
251 
252 struct WeakOrder {
253   int value;
254   constexpr WeakOrder(int v) : value(v) {}
255   friend std::weak_ordering operator<=>(WeakOrder, WeakOrder) = default;
256 };
257 
258 struct PartialOrder {
259   int value;
260   constexpr PartialOrder(int v) : value(v) {}
261   friend constexpr std::partial_ordering operator<=>(PartialOrder lhs, PartialOrder rhs) {
262     if (lhs.value == std::numeric_limits<int>::min() || rhs.value == std::numeric_limits<int>::min())
263       return std::partial_ordering::unordered;
264     if (lhs.value == std::numeric_limits<int>::max() || rhs.value == std::numeric_limits<int>::max())
265       return std::partial_ordering::unordered;
266     return lhs.value <=> rhs.value;
267   }
268   friend constexpr bool operator==(PartialOrder lhs, PartialOrder rhs) {
269     return (lhs <=> rhs) == std::partial_ordering::equivalent;
270   }
271 };
272 
273 #endif
274 
275 #endif // TEST_COMPARISONS_H
276