operator==,!=,<,<=,>,>=(std::unique_ptr)
From cppreference.com
                    
                                        
                    < cpp | memory | unique ptr
                    
                                                            
                    |   template<class T1, class D1, class T2, class D2> 
bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(1) | (since C++11) | 
|   template<class T1, class D1, class T2, class D2> 
bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(2) | (since C++11) | 
|   template<class T1, class D1, class T2, class D2> 
bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(3) | (since C++11) | 
|   template<class T1, class D1, class T2, class D2> 
bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(4) | (since C++11) | 
|   template<class T1, class D1, class T2, class D2> 
bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(5) | (since C++11) | 
|   template<class T1, class D1, class T2, class D2> 
bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);  | 
(6) | (since C++11) | 
|   template <class T, class D> 
bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;  | 
(7) | (since C++11) | 
|   template <class T, class D> 
bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;  | 
(8) | (since C++11) | 
|   template <class T, class D> 
bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;  | 
(9) | (since C++11) | 
|   template <class T, class D> 
bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;  | 
(10) | (since C++11) | 
|   template <class T, class D> 
bool operator<(const unique_ptr<T, D>& x, nullptr_t);  | 
(11) | (since C++11) | 
|   template <class T, class D> 
bool operator<(nullptr_t, const unique_ptr<T, D>& y);  | 
(12) | (since C++11) | 
|   template <class T, class D> 
bool operator<=(const unique_ptr<T, D>& x, nullptr_t);  | 
(13) | (since C++11) | 
|   template <class T, class D> 
bool operator<=(nullptr_t, const unique_ptr<T, D>& y);  | 
(14) | (since C++11) | 
|   template <class T, class D> 
bool operator>(const unique_ptr<T, D>& x, nullptr_t);  | 
(15) | (since C++11) | 
|   template <class T, class D> 
bool operator>(nullptr_t, const unique_ptr<T, D>& y);  | 
(16) | (since C++11) | 
|   template <class T, class D> 
bool operator>=(const unique_ptr<T, D>& x, nullptr_t);  | 
(17) | (since C++11) | 
|   template <class T, class D> 
bool operator>=(nullptr_t, const unique_ptr<T, D>& y);  | 
(18) | (since C++11) | 
Compares the pointer values of two unique_ptrs, or a unique_ptr and nullptr.
1-6) Compares two 
unique_ptrs
7-18) Compares a 
unique_ptr and nullptr.
Contents | 
[edit] Parameters
| x, y | - |   unique_ptrs to compare
 | 
[edit] Return value
1) x.get() == y.get()
2) x.get() != y.get()
3) std::less<CT>()(x.get(), y.get()), where CT is std::common_type<unique_ptr<T1, D1>::pointer, unique_ptr<T2, D2>::pointer>::type
4) !(y < x)
5) y < x
6) !(x < y)
7-8) !x
9-10) (bool)x
11) std::less<unique_ptr<T,D>::pointer>()(x.get(), nullptr)
12) std::less<unique_ptr<T,D>::pointer>()(nullptr, y.get())
13) nullptr < x
14) y < nullptr
15) !(nullptr < x)
16) !(y < nullptr)
17) !(x < nullptr)
18) !(nullptr < y)
[edit] Example
#include <iostream> #include <memory> int main() { std::unique_ptr<int> p1(new int(42)); std::unique_ptr<int> p2(new int(42)); std::cout << "p1 == p1: " << (p1 == p1) << '\n'; // p1 and p2 point to different memory locations, so p1 != p2 std::cout << "p1 == p2: " << (p1 == p2) << '\n'; }
Output:
p1 == p1: 1 p1 == p2: 0
[edit] See also
|    returns a pointer to the managed object   (public member function)  | 
|