unittests/ADT/RangeAdapterTest.cpp

   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:
  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;
  30   reverse_iterator rbegin() { return Vec.rbegin(); }
  31   reverse_iterator rend() { return Vec.rend(); }
  32   const_reverse_iterator rbegin() const { return Vec.rbegin(); }
  33   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:
  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;
  50   reverse_iterator rbegin() const { return Vec.rbegin(); }
  51   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:
  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;
  71   reverse_iterator rbegin() { return Vec.rbegin(); }
  72   reverse_iterator rend() { return Vec.rend(); }
  73   const_reverse_iterator rbegin() const { return Vec.rbegin(); }
  74   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:
  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
  93     explicit reverse_iterator(std::vector<int>::iterator I) : I(I) {}
  94
  95     reverse_iterator &operator++() {
  96       --I;
  97       return *this;
  98     }
  99     reverse_iterator &operator--() {
 100       ++I;
 101       return *this;
 102     }
 103     int &operator*() const { return *std::prev(I); }
 104     int *operator->() const { return &*std::prev(I); }
 105     friend bool operator==(const reverse_iterator &L,
 106                            const reverse_iterator &R) {
 107       return L.I == R.I;
 108     }
 109     friend bool operator!=(const reverse_iterator &L,
 110                            const reverse_iterator &R) {
 111       return !(L == R);
 112     }
 113   };
 114
 115   iterator begin() const { return V.begin(); }
 116   iterator end()  const { return V.end(); }
 117   reverse_iterator rbegin() const { return reverse_iterator(V.end()); }
 118   reverse_iterator rend() const { return reverse_iterator(V.begin()); }
 119 };
 120
 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
 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
 150 TYPED_TEST(RangeAdapterRValueTest, TrivialOperation) {
 151   TestRev(reverse(TypeParam({0, 1, 2, 3})));
 152 }
 153
 154 TYPED_TEST(RangeAdapterRValueTest, HasRbegin) {
 155   static_assert(has_rbegin<TypeParam>::value, "rbegin() should be defined");
 156 }
 157
 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