LSST Applications  21.0.0-172-gfb10e10a+18fedfabac,22.0.0+297cba6710,22.0.0+80564b0ff1,22.0.0+8d77f4f51a,22.0.0+a28f4c53b1,22.0.0+dcf3732eb2,22.0.1-1-g7d6de66+2a20fdde0d,22.0.1-1-g8e32f31+297cba6710,22.0.1-1-geca5380+7fa3b7d9b6,22.0.1-12-g44dc1dc+2a20fdde0d,22.0.1-15-g6a90155+515f58c32b,22.0.1-16-g9282f48+790f5f2caa,22.0.1-2-g92698f7+dcf3732eb2,22.0.1-2-ga9b0f51+7fa3b7d9b6,22.0.1-2-gd1925c9+bf4f0e694f,22.0.1-24-g1ad7a390+a9625a72a8,22.0.1-25-g5bf6245+3ad8ecd50b,22.0.1-25-gb120d7b+8b5510f75f,22.0.1-27-g97737f7+2a20fdde0d,22.0.1-32-gf62ce7b1+aa4237961e,22.0.1-4-g0b3f228+2a20fdde0d,22.0.1-4-g243d05b+871c1b8305,22.0.1-4-g3a563be+32dcf1063f,22.0.1-4-g44f2e3d+9e4ab0f4fa,22.0.1-42-gca6935d93+ba5e5ca3eb,22.0.1-5-g15c806e+85460ae5f3,22.0.1-5-g58711c4+611d128589,22.0.1-5-g75bb458+99c117b92f,22.0.1-6-g1c63a23+7fa3b7d9b6,22.0.1-6-g50866e6+84ff5a128b,22.0.1-6-g8d3140d+720564cf76,22.0.1-6-gd805d02+cc5644f571,22.0.1-8-ge5750ce+85460ae5f3,master-g6e05de7fdc+babf819c66,master-g99da0e417a+8d77f4f51a,w.2021.48
LSST Data Management Base Package
tests.h
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1 // -*- lsst-c++ -*-
2 
3 /*
4  * This file is part of utils.
5  *
6  * Developed for the LSST Data Management System.
7  * This product includes software developed by the LSST Project
8  * (https://www.lsst.org).
9  * See the COPYRIGHT file at the top-level directory of this distribution
10  * for details of code ownership.
11  *
12  * This program is free software: you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation, either version 3 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program. If not, see <https://www.gnu.org/licenses/>.
24  */
25 
26 #ifndef LSST_CPPUTILS_TESTS_H
27 #define LSST_CPPUTILS_TESTS_H
28 
29 // Do not include unit_test.hpp, to avoid definition problems with BOOST_TEST_MODULE
30 
31 #include <ostream>
32 #include <type_traits>
33 
34 namespace lsst {
35 namespace cpputils {
36 
37 namespace {
38 // Variable template reporting whether a type can be printed using <<
39 // Second template parameter is a dummy to let us do some metaprogramming
40 template <typename, typename = void>
41 constexpr bool HAS_STREAM_OUTPUT = false;
42 template <typename T>
43 constexpr bool HAS_STREAM_OUTPUT<
44  T, std::enable_if_t<true, decltype((void)(std::declval<std::ostream&>() << std::declval<T&>()),
45  void())>> = true;
46 
47 // Conditional function templates reporting object values if possible
48 template <typename T, class Hash>
49 std::enable_if_t<HAS_STREAM_OUTPUT<T>> printIfHashEqual(T obj1, T obj2, Hash hash) {
50  BOOST_TEST_REQUIRE(obj1 == obj2);
51  BOOST_TEST(hash(obj1) == hash(obj2),
52  obj1 << " == " << obj2 << ", but " << hash(obj1) << " != " << hash(obj2));
53 }
54 template <typename T, class Hash>
55 std::enable_if_t<!HAS_STREAM_OUTPUT<T>> printIfHashEqual(T obj1, T obj2, Hash hash) {
56  if (!(obj1 == obj2)) {
57  BOOST_FAIL("Unequal objects need not have equal hashes.");
58  }
59  BOOST_TEST(hash(obj1) == hash(obj2));
60 }
61 } // namespace
62 
71 template <typename T>
72 constexpr void assertValidHash() {
73  using namespace std;
74  using Hash = hash<remove_cv_t<T>>;
75 
77  "std::hash specializations must be default-constructible");
78  static_assert(is_copy_assignable<Hash>::value, "std::hash specializations must be copy-assignable");
79  // Swappability hard to test before C++17
80  static_assert(is_destructible<Hash>::value, "std::hash specializations must be destructible");
81 
82  static_assert(is_same<typename Hash::argument_type, remove_cv_t<T>>::value,
83  "std::hash must have an argument_type member until C++20");
85  "std::hash must have a result_type member until C++20");
86  // Ability to call Hash(T) hard to test before C++17
87  static_assert(is_same<result_of_t<Hash(T)>, size_t>::value,
88  "std::hash specializations must be callable and return a size_t");
89 }
90 
101 template <typename T>
102 void assertHashesEqual(T obj1, T obj2) {
103  using Hash = std::hash<std::remove_cv_t<T>>;
104 
105  printIfHashEqual(obj1, obj2, Hash());
106 }
107 
108 } // namespace cpputils
109 namespace utils = cpputils;
110 } // namespace lsst
111 
112 #endif
void assertHashesEqual(T obj1, T obj2)
Test that equal objects have equal hashes.
Definition: tests.h:102
constexpr void assertValidHash()
Compile-time test of whether a specialization of std::hash conforms to the general spec.
Definition: tests.h:72
A base class for image defects.
STL namespace.