clang-tools-extra/test/clang-tidy/checkers/readability/container-contains.cpp - toolchain/llvm-project - Git at Google

 // RUN: %check_clang_tidy -std=c++11-or-later %s readability-container-contains %t

 // Some *very* simplified versions of `map` etc.
 namespace std {

 template <class Key, class T>
 struct map {
   struct iterator {
     bool operator==(const iterator &Other) const;
     bool operator!=(const iterator &Other) const;
   };

   unsigned count(const Key &K) const;
   bool contains(const Key &K) const;
   iterator find(const Key &K);
   iterator end();
 };

 template <class Key>
 struct set {
   unsigned count(const Key &K) const;
   bool contains(const Key &K) const;
 };

 template <class Key>
 struct unordered_set {
   unsigned count(const Key &K) const;
   bool contains(const Key &K) const;
 };

 template <class Key, class T>
 struct multimap {
   unsigned count(const Key &K) const;
   bool contains(const Key &K) const;
 };

 } // namespace std

 // Check that we detect various common ways to check for membership
 int testDifferentCheckTypes(std::map<int, int> &MyMap) {
   if (MyMap.count(0))
     // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use 'contains' to check for membership [readability-container-contains]
     // CHECK-FIXES: if (MyMap.contains(0))
     return 1;
   bool C1 = MyMap.count(1);
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C1 = MyMap.contains(1);
   auto C2 = static_cast<bool>(MyMap.count(1));
   // CHECK-MESSAGES: :[[@LINE-1]]:37: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C2 = static_cast<bool>(MyMap.contains(1));
   auto C3 = MyMap.count(2) != 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C3 = MyMap.contains(2);
   auto C4 = MyMap.count(3) > 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C4 = MyMap.contains(3);
   auto C5 = MyMap.count(4) >= 1;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C5 = MyMap.contains(4);
   auto C6 = MyMap.find(5) != MyMap.end();
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C6 = MyMap.contains(5);
   return C1 + C2 + C3 + C4 + C5 + C6;
 }

 // Check that we detect various common ways to check for non-membership
 int testNegativeChecks(std::map<int, int> &MyMap) {
   bool C1 = !MyMap.count(-1);
   // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C1 = !MyMap.contains(-1);
   auto C2 = MyMap.count(-2) == 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C2 = !MyMap.contains(-2);
   auto C3 = MyMap.count(-3) <= 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C3 = !MyMap.contains(-3);
   auto C4 = MyMap.count(-4) < 1;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C4 = !MyMap.contains(-4);
   auto C5 = MyMap.find(-5) == MyMap.end();
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C5 = !MyMap.contains(-5);
   return C1 + C2 + C3 + C4 + C5;
 }

 // Check for various types
 int testDifferentTypes(std::map<int, int> &M, std::unordered_set<int> &US, std::set<int> &S, std::multimap<int, int> &MM) {
   bool C1 = M.count(1001);
   // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C1 = M.contains(1001);
   bool C2 = US.count(1002);
   // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C2 = US.contains(1002);
   bool C3 = S.count(1003);
   // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C3 = S.contains(1003);
   bool C4 = MM.count(1004);
   // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C4 = MM.contains(1004);
   return C1 + C2 + C3 + C4;
 }

 // The check detects all kind of `const`, reference, rvalue-reference and value types.
 int testQualifiedTypes(std::map<int, int> ValueM, std::map<int, int> &RefM, const std::map<int, int> &ConstRefM, std::map<int, int> &&RValueM) {
   bool C1 = ValueM.count(2001);
   // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C1 = ValueM.contains(2001);
   bool C2 = RefM.count(2002);
   // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C2 = RefM.contains(2002);
   bool C3 = ConstRefM.count(2003);
   // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C3 = ConstRefM.contains(2003);
   bool C4 = RValueM.count(2004);
   // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C4 = RValueM.contains(2004);
   return C1 + C2 + C3 + C4;
 }

 // This is effectively a membership check, as the result is implicitly casted
 // to `bool`.
 bool returnContains(std::map<int, int> &M) {
   return M.count(42);
   // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: return M.contains(42);
 }

 // This returns the actual count and should not be rewritten
 int actualCount(std::multimap<int, int> &M) {
   return M.count(21);
   // NO-WARNING.
   // CHECK-FIXES: return M.count(21);
 }

 // Check that we are not confused by aliases
 namespace s2 = std;
 using MyMapT = s2::map<int, int>;
 int typeAliases(MyMapT &MyMap) {
   bool C1 = MyMap.count(99);
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: bool C1 = MyMap.contains(99);
   return C1;
 }

 // Check that the tests also trigger for a local variable and not only for
 // function arguments.
 bool localVar() {
   using namespace std;
   map<int, int> LocalM;
   return LocalM.count(42);
   // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: return LocalM.contains(42);
 }

 // Check various usages of an actual `count` which isn't rewritten
 int nonRewrittenCount(std::multimap<int, int> &MyMap) {
   // This is an actual test if we have at least 2 usages. Shouldn't be rewritten.
   bool C1 = MyMap.count(1) >= 2;
   // NO-WARNING.
   // CHECK-FIXES: bool C1 = MyMap.count(1) >= 2;

   // "< 0" makes little sense and is always `false`. Still, let's ensure we
   // don't accidentally rewrite it to 'contains'.
   bool C2 = MyMap.count(2) < 0;
   // NO-WARNING.
   // CHECK-FIXES: bool C2 = MyMap.count(2) < 0;

   // The `count` is used in some more complicated formula.
   bool C3 = MyMap.count(1) + MyMap.count(2) * 2 + MyMap.count(3) / 3 >= 20;
   // NO-WARNING.
   // CHECK-FIXES: bool C3 = MyMap.count(1) + MyMap.count(2) * 2 + MyMap.count(3) / 3 >= 20;

   // This could theoretically be rewritten into a 'contains' after removig the
   // `4` on both sides of the comparison. For the time being, we don't detect
   // this case.
   bool C4 = MyMap.count(1) + 4 > 4;
   // NO-WARNING.
   // CHECK-FIXES: bool C4 = MyMap.count(1) + 4 > 4;

   return C1 + C2 + C3 + C4;
 }

 // Check different integer literal suffixes
 int testDifferentIntegerLiteralSuffixes(std::map<int, int> &MyMap) {

   auto C1 = MyMap.count(2) != 0U;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C1 = MyMap.contains(2);
   auto C2 = MyMap.count(2) != 0UL;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C2 = MyMap.contains(2);
   auto C3 = 0U != MyMap.count(2);
   // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C3 = MyMap.contains(2);
   auto C4 = 0UL != MyMap.count(2);
   // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C4 = MyMap.contains(2);
   auto C5 = MyMap.count(2) < 1U;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C5 = !MyMap.contains(2);
   auto C6 = MyMap.count(2) < 1UL;
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C6 = !MyMap.contains(2);
   auto C7 = 1U > MyMap.count(2);
   // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C7 = !MyMap.contains(2);
   auto C8 = 1UL > MyMap.count(2);
   // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: auto C8 = !MyMap.contains(2);

   return C1 + C2 + C3 + C4 + C5 + C6 + C7 + C8;
 }

 // We don't want to rewrite if the `contains` call is from a macro expansion
 int testMacroExpansion(std::unordered_set<int> &MySet) {
 #define COUNT_ONES(SET) SET.count(1)
   // Rewriting the macro would break the code
   // CHECK-FIXES: #define COUNT_ONES(SET) SET.count(1)
   // We still want to warn the user even if we don't offer a fixit
   if (COUNT_ONES(MySet)) {
     // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'contains' to check for membership [readability-container-contains]
     // CHECK-MESSAGES: note: expanded from macro 'COUNT_ONES'
     return COUNT_ONES(MySet);
   }
 #undef COUNT_ONES
 #define COUNT_ONES count(1)
   // Rewriting the macro would break the code
   // CHECK-FIXES: #define COUNT_ONES count(1)
   // We still want to warn the user even if we don't offer a fixit
   if (MySet.COUNT_ONES) {
     // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use 'contains' to check for membership [readability-container-contains]
     // CHECK-MESSAGES: note: expanded from macro 'COUNT_ONES'
     return MySet.COUNT_ONES;
   }
 #undef COUNT_ONES
 #define MY_SET MySet
   // CHECK-FIXES: #define MY_SET MySet
   // We still want to rewrite one of the two calls to `count`
   if (MY_SET.count(1)) {
     // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use 'contains' to check for membership [readability-container-contains]
     // CHECK-FIXES: if (MY_SET.contains(1)) {
     return MY_SET.count(1);
   }
 #undef MY_SET
   return 0;
 }

 // The following map has the same interface as `std::map`.
 template <class Key, class T>
 struct CustomMap {
   unsigned count(const Key &K) const;
   bool contains(const Key &K) const;
   void *find(const Key &K);
   void *end();
 };

 void testDifferentCheckTypes(CustomMap<int, int> &MyMap) {
   if (MyMap.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap.contains(0)) {};

   MyMap.find(0) != MyMap.end();
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: MyMap.contains(0);
 }

 struct MySubmap : public CustomMap<int, int> {};

 void testSubclass(MySubmap& MyMap) {
   if (MyMap.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap.contains(0)) {};
 }

 using UsingMap = CustomMap<int, int>;
 struct MySubmap2 : public UsingMap {};
 using UsingMap2 = MySubmap2;

 void testUsing(UsingMap2& MyMap) {
   if (MyMap.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap.contains(0)) {};
 }

 template <class Key, class T>
 struct CustomMapContainsDeleted {
   unsigned count(const Key &K) const;
   bool contains(const Key &K) const = delete;
   void *find(const Key &K);
   void *end();
 };

 struct SubmapContainsDeleted : public CustomMapContainsDeleted<int, int> {};

 void testContainsDeleted(CustomMapContainsDeleted<int, int> &MyMap,
                          SubmapContainsDeleted &MyMap2) {
   // No warning if the `contains` method is deleted.
   if (MyMap.count(0)) {};
   if (MyMap2.count(0)) {};
 }

 template <class Key, class T>
 struct CustomMapPrivateContains {
   unsigned count(const Key &K) const;
   void *find(const Key &K);
   void *end();

 private:
   bool contains(const Key &K) const;
 };

 struct SubmapPrivateContains : public CustomMapPrivateContains<int, int> {};

 void testPrivateContains(CustomMapPrivateContains<int, int> &MyMap,
                          SubmapPrivateContains &MyMap2) {
   // No warning if the `contains` method is not public.
   if (MyMap.count(0)) {};
   if (MyMap2.count(0)) {};
 }

 struct MyString {};

 struct WeirdNonMatchingContains {
   unsigned count(char) const;
   bool contains(const MyString&) const;
 };

 void testWeirdNonMatchingContains(WeirdNonMatchingContains &MyMap) {
   // No warning if there is no `contains` method with the right type.
   if (MyMap.count('a')) {};
 }

 template <class T>
 struct SmallPtrSet {
   using ConstPtrType = const T*;
   unsigned count(ConstPtrType Ptr) const;
   bool contains(ConstPtrType Ptr) const;
 };

 template <class T>
 struct SmallPtrPtrSet {
   using ConstPtrType = const T**;
   unsigned count(ConstPtrType Ptr) const;
   bool contains(ConstPtrType Ptr) const;
 };

 template <class T>
 struct SmallPtrPtrPtrSet {
   using ConstPtrType = const T***;
   unsigned count(ConstPtrType Ptr) const;
   bool contains(ConstPtrType Ptr) const;
 };

 void testSmallPtrSet(const int ***Ptr,
                      SmallPtrSet<int> &MySet,
                      SmallPtrPtrSet<int> &MySet2,
                      SmallPtrPtrPtrSet<int> &MySet3) {
   if (MySet.count(**Ptr)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MySet.contains(**Ptr)) {};
   if (MySet2.count(*Ptr)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MySet2.contains(*Ptr)) {};
   if (MySet3.count(Ptr)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MySet3.contains(Ptr)) {};
 }

 struct X {};
 struct Y : public X {};

 void testSubclassEntry(SmallPtrSet<X>& Set, Y* Entry) {
   if (Set.count(Entry)) {}
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Set.contains(Entry)) {}
 }

 struct WeirdPointerApi {
   unsigned count(int** Ptr) const;
   bool contains(int* Ptr) const;
 };

 void testWeirdApi(WeirdPointerApi& Set, int* E) {
   if (Set.count(&E)) {}
 }

 void testIntUnsigned(std::set<int>& S, unsigned U) {
   if (S.count(U)) {}
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (S.contains(U)) {}
 }

 template <class T>
 struct CustomSetConvertible {
   unsigned count(const T &K) const;
   bool contains(const T &K) const;
 };

 struct A {};
 struct B { B() = default; B(const A&) {} };
 struct C { operator A() const; };

 void testConvertibleTypes() {
   CustomSetConvertible<B> MyMap;
   if (MyMap.count(A())) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap.contains(A())) {};

   CustomSetConvertible<A> MyMap2;
   if (MyMap2.count(C())) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap2.contains(C())) {};

   if (MyMap2.count(C()) != 0) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (MyMap2.contains(C())) {};
 }

 template<class U>
 using Box = const U& ;

 template <class T>
 struct CustomBoxedSet {
   unsigned count(Box<T> K) const;
   bool contains(Box<T> K) const;
 };

 void testBox() {
   CustomBoxedSet<int> Set;
   if (Set.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Set.contains(0)) {};
 }

 void testOperandPermutations(std::map<int, int>& Map) {
   if (Map.count(0) != 0) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Map.contains(0)) {};
   if (0 != Map.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Map.contains(0)) {};
   if (Map.count(0) == 0) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (!Map.contains(0)) {};
   if (0 == Map.count(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (!Map.contains(0)) {};
   if (Map.find(0) != Map.end()) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Map.contains(0)) {};
   if (Map.end() != Map.find(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (Map.contains(0)) {};
   if (Map.find(0) == Map.end()) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (!Map.contains(0)) {};
   if (Map.end() == Map.find(0)) {};
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
   // CHECK-FIXES: if (!Map.contains(0)) {};
 }
	// RUN: %check_clang_tidy -std=c++11-or-later %s readability-container-contains %t

	// Some very simplified versions of `map` etc.
	namespace std {

	template <class Key, class T>
	struct map {
	struct iterator {
	bool operator==(const iterator &Other) const;
	bool operator!=(const iterator &Other) const;
	};

	unsigned count(const Key &K) const;
	bool contains(const Key &K) const;
	iterator find(const Key &K);
	iterator end();
	};

	template <class Key>
	struct set {
	unsigned count(const Key &K) const;
	bool contains(const Key &K) const;
	};

	template <class Key>
	struct unordered_set {
	unsigned count(const Key &K) const;
	bool contains(const Key &K) const;
	};

	template <class Key, class T>
	struct multimap {
	unsigned count(const Key &K) const;
	bool contains(const Key &K) const;
	};

	} // namespace std

	// Check that we detect various common ways to check for membership
	int testDifferentCheckTypes(std::map<int, int> &MyMap) {
	if (MyMap.count(0))
	// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap.contains(0))
	return 1;
	bool C1 = MyMap.count(1);
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C1 = MyMap.contains(1);
	auto C2 = static_cast<bool>(MyMap.count(1));
	// CHECK-MESSAGES: :[[@LINE-1]]:37: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C2 = static_cast<bool>(MyMap.contains(1));
	auto C3 = MyMap.count(2) != 0;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C3 = MyMap.contains(2);
	auto C4 = MyMap.count(3) > 0;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C4 = MyMap.contains(3);
	auto C5 = MyMap.count(4) >= 1;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C5 = MyMap.contains(4);
	auto C6 = MyMap.find(5) != MyMap.end();
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C6 = MyMap.contains(5);
	return C1 + C2 + C3 + C4 + C5 + C6;
	}

	// Check that we detect various common ways to check for non-membership
	int testNegativeChecks(std::map<int, int> &MyMap) {
	bool C1 = !MyMap.count(-1);
	// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C1 = !MyMap.contains(-1);
	auto C2 = MyMap.count(-2) == 0;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C2 = !MyMap.contains(-2);
	auto C3 = MyMap.count(-3) <= 0;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C3 = !MyMap.contains(-3);
	auto C4 = MyMap.count(-4) < 1;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C4 = !MyMap.contains(-4);
	auto C5 = MyMap.find(-5) == MyMap.end();
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C5 = !MyMap.contains(-5);
	return C1 + C2 + C3 + C4 + C5;
	}

	// Check for various types
	int testDifferentTypes(std::map<int, int> &M, std::unordered_set<int> &US, std::set<int> &S, std::multimap<int, int> &MM) {
	bool C1 = M.count(1001);
	// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C1 = M.contains(1001);
	bool C2 = US.count(1002);
	// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C2 = US.contains(1002);
	bool C3 = S.count(1003);
	// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C3 = S.contains(1003);
	bool C4 = MM.count(1004);
	// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C4 = MM.contains(1004);
	return C1 + C2 + C3 + C4;
	}

	// The check detects all kind of `const`, reference, rvalue-reference and value types.
	int testQualifiedTypes(std::map<int, int> ValueM, std::map<int, int> &RefM, const std::map<int, int> &ConstRefM, std::map<int, int> &&RValueM) {
	bool C1 = ValueM.count(2001);
	// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C1 = ValueM.contains(2001);
	bool C2 = RefM.count(2002);
	// CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C2 = RefM.contains(2002);
	bool C3 = ConstRefM.count(2003);
	// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C3 = ConstRefM.contains(2003);
	bool C4 = RValueM.count(2004);
	// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C4 = RValueM.contains(2004);
	return C1 + C2 + C3 + C4;
	}

	// This is effectively a membership check, as the result is implicitly casted
	// to `bool`.
	bool returnContains(std::map<int, int> &M) {
	return M.count(42);
	// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: return M.contains(42);
	}

	// This returns the actual count and should not be rewritten
	int actualCount(std::multimap<int, int> &M) {
	return M.count(21);
	// NO-WARNING.
	// CHECK-FIXES: return M.count(21);
	}

	// Check that we are not confused by aliases
	namespace s2 = std;
	using MyMapT = s2::map<int, int>;
	int typeAliases(MyMapT &MyMap) {
	bool C1 = MyMap.count(99);
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: bool C1 = MyMap.contains(99);
	return C1;
	}

	// Check that the tests also trigger for a local variable and not only for
	// function arguments.
	bool localVar() {
	using namespace std;
	map<int, int> LocalM;
	return LocalM.count(42);
	// CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: return LocalM.contains(42);
	}

	// Check various usages of an actual `count` which isn't rewritten
	int nonRewrittenCount(std::multimap<int, int> &MyMap) {
	// This is an actual test if we have at least 2 usages. Shouldn't be rewritten.
	bool C1 = MyMap.count(1) >= 2;
	// NO-WARNING.
	// CHECK-FIXES: bool C1 = MyMap.count(1) >= 2;

	// "< 0" makes little sense and is always `false`. Still, let's ensure we
	// don't accidentally rewrite it to 'contains'.
	bool C2 = MyMap.count(2) < 0;
	// NO-WARNING.
	// CHECK-FIXES: bool C2 = MyMap.count(2) < 0;

	// The `count` is used in some more complicated formula.
	bool C3 = MyMap.count(1) + MyMap.count(2) * 2 + MyMap.count(3) / 3 >= 20;
	// NO-WARNING.
	// CHECK-FIXES: bool C3 = MyMap.count(1) + MyMap.count(2) * 2 + MyMap.count(3) / 3 >= 20;

	// This could theoretically be rewritten into a 'contains' after removig the
	// `4` on both sides of the comparison. For the time being, we don't detect
	// this case.
	bool C4 = MyMap.count(1) + 4 > 4;
	// NO-WARNING.
	// CHECK-FIXES: bool C4 = MyMap.count(1) + 4 > 4;

	return C1 + C2 + C3 + C4;
	}

	// Check different integer literal suffixes
	int testDifferentIntegerLiteralSuffixes(std::map<int, int> &MyMap) {

	auto C1 = MyMap.count(2) != 0U;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C1 = MyMap.contains(2);
	auto C2 = MyMap.count(2) != 0UL;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C2 = MyMap.contains(2);
	auto C3 = 0U != MyMap.count(2);
	// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C3 = MyMap.contains(2);
	auto C4 = 0UL != MyMap.count(2);
	// CHECK-MESSAGES: :[[@LINE-1]]:26: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C4 = MyMap.contains(2);
	auto C5 = MyMap.count(2) < 1U;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C5 = !MyMap.contains(2);
	auto C6 = MyMap.count(2) < 1UL;
	// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C6 = !MyMap.contains(2);
	auto C7 = 1U > MyMap.count(2);
	// CHECK-MESSAGES: :[[@LINE-1]]:24: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C7 = !MyMap.contains(2);
	auto C8 = 1UL > MyMap.count(2);
	// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: auto C8 = !MyMap.contains(2);

	return C1 + C2 + C3 + C4 + C5 + C6 + C7 + C8;
	}

	// We don't want to rewrite if the `contains` call is from a macro expansion
	int testMacroExpansion(std::unordered_set<int> &MySet) {
	#define COUNT_ONES(SET) SET.count(1)
	// Rewriting the macro would break the code
	// CHECK-FIXES: #define COUNT_ONES(SET) SET.count(1)
	// We still want to warn the user even if we don't offer a fixit
	if (COUNT_ONES(MySet)) {
	// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-MESSAGES: note: expanded from macro 'COUNT_ONES'
	return COUNT_ONES(MySet);
	}
	#undef COUNT_ONES
	#define COUNT_ONES count(1)
	// Rewriting the macro would break the code
	// CHECK-FIXES: #define COUNT_ONES count(1)
	// We still want to warn the user even if we don't offer a fixit
	if (MySet.COUNT_ONES) {
	// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-MESSAGES: note: expanded from macro 'COUNT_ONES'
	return MySet.COUNT_ONES;
	}
	#undef COUNT_ONES
	#define MY_SET MySet
	// CHECK-FIXES: #define MY_SET MySet
	// We still want to rewrite one of the two calls to `count`
	if (MY_SET.count(1)) {
	// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MY_SET.contains(1)) {
	return MY_SET.count(1);
	}
	#undef MY_SET
	return 0;
	}

	// The following map has the same interface as `std::map`.
	template <class Key, class T>
	struct CustomMap {
	unsigned count(const Key &K) const;
	bool contains(const Key &K) const;
	void *find(const Key &K);
	void *end();
	};

	void testDifferentCheckTypes(CustomMap<int, int> &MyMap) {
	if (MyMap.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap.contains(0)) {};

	MyMap.find(0) != MyMap.end();
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: MyMap.contains(0);
	}

	struct MySubmap : public CustomMap<int, int> {};

	void testSubclass(MySubmap& MyMap) {
	if (MyMap.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap.contains(0)) {};
	}

	using UsingMap = CustomMap<int, int>;
	struct MySubmap2 : public UsingMap {};
	using UsingMap2 = MySubmap2;

	void testUsing(UsingMap2& MyMap) {
	if (MyMap.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap.contains(0)) {};
	}

	template <class Key, class T>
	struct CustomMapContainsDeleted {
	unsigned count(const Key &K) const;
	bool contains(const Key &K) const = delete;
	void *find(const Key &K);
	void *end();
	};

	struct SubmapContainsDeleted : public CustomMapContainsDeleted<int, int> {};

	void testContainsDeleted(CustomMapContainsDeleted<int, int> &MyMap,
	SubmapContainsDeleted &MyMap2) {
	// No warning if the `contains` method is deleted.
	if (MyMap.count(0)) {};
	if (MyMap2.count(0)) {};
	}

	template <class Key, class T>
	struct CustomMapPrivateContains {
	unsigned count(const Key &K) const;
	void *find(const Key &K);
	void *end();

	private:
	bool contains(const Key &K) const;
	};

	struct SubmapPrivateContains : public CustomMapPrivateContains<int, int> {};

	void testPrivateContains(CustomMapPrivateContains<int, int> &MyMap,
	SubmapPrivateContains &MyMap2) {
	// No warning if the `contains` method is not public.
	if (MyMap.count(0)) {};
	if (MyMap2.count(0)) {};
	}

	struct MyString {};

	struct WeirdNonMatchingContains {
	unsigned count(char) const;
	bool contains(const MyString&) const;
	};

	void testWeirdNonMatchingContains(WeirdNonMatchingContains &MyMap) {
	// No warning if there is no `contains` method with the right type.
	if (MyMap.count('a')) {};
	}

	template <class T>
	struct SmallPtrSet {
	using ConstPtrType = const T*;
	unsigned count(ConstPtrType Ptr) const;
	bool contains(ConstPtrType Ptr) const;
	};

	template <class T>
	struct SmallPtrPtrSet {
	using ConstPtrType = const T**;
	unsigned count(ConstPtrType Ptr) const;
	bool contains(ConstPtrType Ptr) const;
	};

	template <class T>
	struct SmallPtrPtrPtrSet {
	using ConstPtrType = const T***;
	unsigned count(ConstPtrType Ptr) const;
	bool contains(ConstPtrType Ptr) const;
	};

	void testSmallPtrSet(const int ***Ptr,
	SmallPtrSet<int> &MySet,
	SmallPtrPtrSet<int> &MySet2,
	SmallPtrPtrPtrSet<int> &MySet3) {
	if (MySet.count(**Ptr)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MySet.contains(**Ptr)) {};
	if (MySet2.count(*Ptr)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MySet2.contains(*Ptr)) {};
	if (MySet3.count(Ptr)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MySet3.contains(Ptr)) {};
	}

	struct X {};
	struct Y : public X {};

	void testSubclassEntry(SmallPtrSet<X>& Set, Y* Entry) {
	if (Set.count(Entry)) {}
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Set.contains(Entry)) {}
	}

	struct WeirdPointerApi {
	unsigned count(int** Ptr) const;
	bool contains(int* Ptr) const;
	};

	void testWeirdApi(WeirdPointerApi& Set, int* E) {
	if (Set.count(&E)) {}
	}

	void testIntUnsigned(std::set<int>& S, unsigned U) {
	if (S.count(U)) {}
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (S.contains(U)) {}
	}

	template <class T>
	struct CustomSetConvertible {
	unsigned count(const T &K) const;
	bool contains(const T &K) const;
	};

	struct A {};
	struct B { B() = default; B(const A&) {} };
	struct C { operator A() const; };

	void testConvertibleTypes() {
	CustomSetConvertible<B> MyMap;
	if (MyMap.count(A())) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap.contains(A())) {};

	CustomSetConvertible<A> MyMap2;
	if (MyMap2.count(C())) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap2.contains(C())) {};

	if (MyMap2.count(C()) != 0) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (MyMap2.contains(C())) {};
	}

	template<class U>
	using Box = const U& ;

	template <class T>
	struct CustomBoxedSet {
	unsigned count(Box<T> K) const;
	bool contains(Box<T> K) const;
	};

	void testBox() {
	CustomBoxedSet<int> Set;
	if (Set.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Set.contains(0)) {};
	}

	void testOperandPermutations(std::map<int, int>& Map) {
	if (Map.count(0) != 0) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Map.contains(0)) {};
	if (0 != Map.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Map.contains(0)) {};
	if (Map.count(0) == 0) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (!Map.contains(0)) {};
	if (0 == Map.count(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (!Map.contains(0)) {};
	if (Map.find(0) != Map.end()) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Map.contains(0)) {};
	if (Map.end() != Map.find(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (Map.contains(0)) {};
	if (Map.find(0) == Map.end()) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (!Map.contains(0)) {};
	if (Map.end() == Map.find(0)) {};
	// CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use 'contains' to check for membership [readability-container-contains]
	// CHECK-FIXES: if (!Map.contains(0)) {};
	}