misc-unconventional-assign-operator.cpp

// RUN: %check_clang_tidy %s misc-unconventional-assign-operator %t -- -- -std=c++11 -isystem %S/Inputs/Headers

#include <utility>

struct Good {
  Good& operator=(const Good&);
  Good& operator=(Good&&);

  // Assign from other types is fine too.
  Good& operator=(int);
};

struct AlsoGood {
  // By value is also fine.
  AlsoGood& operator=(AlsoGood);
};

struct BadReturnType {
  void operator=(const BadReturnType&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'BadReturnType&' [misc-unconventional-assign-operator]
  const BadReturnType& operator=(BadReturnType&&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'Bad
  void operator=(int);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'Bad
};

struct BadReturnType2 {
  BadReturnType2&& operator=(const BadReturnType2&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'Bad
  int operator=(BadReturnType2&&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'Bad
};

struct BadArgument {
  BadArgument& operator=(BadArgument&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should take 'BadArgument const&', 'BadArgument&&' or 'BadArgument'
  BadArgument& operator=(const BadArgument&&);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should take 'BadAr
};

struct BadModifier {
  BadModifier& operator=(const BadModifier&) const;
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should not be marked 'const'
};

struct Deleted {
  // We don't check the return value of deleted operators.
  void operator=(const Deleted&) = delete;
  void operator=(Deleted&&) = delete;
};

class Private {
  // We don't check the return value of private operators.
  // Pre-C++11 way of disabling assignment.
  void operator=(const Private &);
};

struct Virtual {
  virtual Virtual& operator=(const Virtual &);
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should not be marked 'virtual'
};

class BadReturnStatement {
  int n;

public:
  BadReturnStatement& operator=(BadReturnStatement&& rhs) {
    n = std::move(rhs.n);
    return rhs;
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: operator=() should always return '*this'
  }

  // Do not check if return type is different from '&BadReturnStatement'
  int operator=(int i) {
  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: operator=() should return 'Bad
    n = i;
    return n;
  }
};