1 //===- RangeAdapterTest.cpp - Unit tests for range adapters --------------===//
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
9 #include "llvm/ADT/STLExtras.h"
10 #include "llvm/ADT/iterator_range.h"
11 #include "gtest/gtest.h"
12
13 #include <iterator>
14 #include <list>
15 #include <vector>
16
17 using namespace llvm;
18
19 namespace {
20
21 // A wrapper around vector which exposes rbegin(), rend().
22 class ReverseOnlyVector {
23 std::vector<int> Vec;
24
25 public:
ReverseOnlyVector(std::initializer_list<int> list)26 ReverseOnlyVector(std::initializer_list<int> list) : Vec(list) {}
27
28 typedef std::vector<int>::reverse_iterator reverse_iterator;
29 typedef std::vector<int>::const_reverse_iterator const_reverse_iterator;
rbegin()30 reverse_iterator rbegin() { return Vec.rbegin(); }
rend()31 reverse_iterator rend() { return Vec.rend(); }
rbegin() const32 const_reverse_iterator rbegin() const { return Vec.rbegin(); }
rend() const33 const_reverse_iterator rend() const { return Vec.rend(); }
34 };
35
36 // A wrapper around vector which exposes begin(), end(), rbegin() and rend().
37 // begin() and end() don't have implementations as this ensures that we will
38 // get a linker error if reverse() chooses begin()/end() over rbegin(), rend().
39 class BidirectionalVector {
40 mutable std::vector<int> Vec;
41
42 public:
BidirectionalVector(std::initializer_list<int> list)43 BidirectionalVector(std::initializer_list<int> list) : Vec(list) {}
44
45 typedef std::vector<int>::iterator iterator;
46 iterator begin() const;
47 iterator end() const;
48
49 typedef std::vector<int>::reverse_iterator reverse_iterator;
rbegin() const50 reverse_iterator rbegin() const { return Vec.rbegin(); }
rend() const51 reverse_iterator rend() const { return Vec.rend(); }
52 };
53
54 /// This is the same as BidirectionalVector but with the addition of const
55 /// begin/rbegin methods to ensure that the type traits for has_rbegin works.
56 class BidirectionalVectorConsts {
57 std::vector<int> Vec;
58
59 public:
BidirectionalVectorConsts(std::initializer_list<int> list)60 BidirectionalVectorConsts(std::initializer_list<int> list) : Vec(list) {}
61
62 typedef std::vector<int>::iterator iterator;
63 typedef std::vector<int>::const_iterator const_iterator;
64 iterator begin();
65 iterator end();
66 const_iterator begin() const;
67 const_iterator end() const;
68
69 typedef std::vector<int>::reverse_iterator reverse_iterator;
70 typedef std::vector<int>::const_reverse_iterator const_reverse_iterator;
rbegin()71 reverse_iterator rbegin() { return Vec.rbegin(); }
rend()72 reverse_iterator rend() { return Vec.rend(); }
rbegin() const73 const_reverse_iterator rbegin() const { return Vec.rbegin(); }
rend() const74 const_reverse_iterator rend() const { return Vec.rend(); }
75 };
76
77 /// Check that types with custom iterators work.
78 class CustomIteratorVector {
79 mutable std::vector<int> V;
80
81 public:
CustomIteratorVector(std::initializer_list<int> list)82 CustomIteratorVector(std::initializer_list<int> list) : V(list) {}
83
84 typedef std::vector<int>::iterator iterator;
85 class reverse_iterator {
86 std::vector<int>::iterator I;
87
88 public:
89 reverse_iterator() = default;
90 reverse_iterator(const reverse_iterator &) = default;
91 reverse_iterator &operator=(const reverse_iterator &) = default;
92
reverse_iterator(std::vector<int>::iterator I)93 explicit reverse_iterator(std::vector<int>::iterator I) : I(I) {}
94
operator ++()95 reverse_iterator &operator++() {
96 --I;
97 return *this;
98 }
operator --()99 reverse_iterator &operator--() {
100 ++I;
101 return *this;
102 }
operator *() const103 int &operator*() const { return *std::prev(I); }
operator ->() const104 int *operator->() const { return &*std::prev(I); }
operator ==(const reverse_iterator & L,const reverse_iterator & R)105 friend bool operator==(const reverse_iterator &L,
106 const reverse_iterator &R) {
107 return L.I == R.I;
108 }
operator !=(const reverse_iterator & L,const reverse_iterator & R)109 friend bool operator!=(const reverse_iterator &L,
110 const reverse_iterator &R) {
111 return !(L == R);
112 }
113 };
114
begin() const115 iterator begin() const { return V.begin(); }
end() const116 iterator end() const { return V.end(); }
rbegin() const117 reverse_iterator rbegin() const { return reverse_iterator(V.end()); }
rend() const118 reverse_iterator rend() const { return reverse_iterator(V.begin()); }
119 };
120
TestRev(const R & r)121 template <typename R> void TestRev(const R &r) {
122 int counter = 3;
123 for (int i : r)
124 EXPECT_EQ(i, counter--);
125 }
126
127 // Test fixture
128 template <typename T> class RangeAdapterLValueTest : public ::testing::Test {};
129
130 typedef ::testing::Types<std::vector<int>, std::list<int>, int[4]>
131 RangeAdapterLValueTestTypes;
132 TYPED_TEST_CASE(RangeAdapterLValueTest, RangeAdapterLValueTestTypes);
133
TYPED_TEST(RangeAdapterLValueTest,TrivialOperation)134 TYPED_TEST(RangeAdapterLValueTest, TrivialOperation) {
135 TypeParam v = {0, 1, 2, 3};
136 TestRev(reverse(v));
137
138 const TypeParam c = {0, 1, 2, 3};
139 TestRev(reverse(c));
140 }
141
142 template <typename T> struct RangeAdapterRValueTest : testing::Test {};
143
144 typedef ::testing::Types<std::vector<int>, std::list<int>, CustomIteratorVector,
145 ReverseOnlyVector, BidirectionalVector,
146 BidirectionalVectorConsts>
147 RangeAdapterRValueTestTypes;
148 TYPED_TEST_CASE(RangeAdapterRValueTest, RangeAdapterRValueTestTypes);
149
TYPED_TEST(RangeAdapterRValueTest,TrivialOperation)150 TYPED_TEST(RangeAdapterRValueTest, TrivialOperation) {
151 TestRev(reverse(TypeParam({0, 1, 2, 3})));
152 }
153
TYPED_TEST(RangeAdapterRValueTest,HasRbegin)154 TYPED_TEST(RangeAdapterRValueTest, HasRbegin) {
155 static_assert(has_rbegin<TypeParam>::value, "rbegin() should be defined");
156 }
157
TYPED_TEST(RangeAdapterRValueTest,RangeType)158 TYPED_TEST(RangeAdapterRValueTest, RangeType) {
159 static_assert(
160 std::is_same<
161 decltype(reverse(*static_cast<TypeParam *>(nullptr)).begin()),
162 decltype(static_cast<TypeParam *>(nullptr)->rbegin())>::value,
163 "reverse().begin() should have the same type as rbegin()");
164 static_assert(
165 std::is_same<
166 decltype(reverse(*static_cast<const TypeParam *>(nullptr)).begin()),
167 decltype(static_cast<const TypeParam *>(nullptr)->rbegin())>::value,
168 "reverse().begin() should have the same type as rbegin() [const]");
169 }
170
171 } // anonymous namespace
172