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std::shared_ptr::operator==, !=, <, <=, >, >=

From cppreference.com
 
 
 
 
 
template <class T, class U>
    bool operator==(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(1)
template <class T, class U>
    bool operator!=(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(2)
template <class T, class U>
    bool operator<(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(3)
template <class T, class U>
    bool operator>(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(4)
template <class T, class U>
    bool operator<=(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(5)
template <class T, class U>
    bool operator>=(const shared_ptr<T>& lhs, const shared_ptr<U>& rhs);
(6)
template <class T>
    bool operator==(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(7)
template <class T>
    bool operator==(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(8)
template <class T>
    bool operator!=(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(9)
template <class T>
    bool operator!=(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(10)
template <class T>
    bool operator<(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(11)
template <class T>
    bool operator<(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(12)
template <class T>
    bool operator<=(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(13)
template <class T>
    bool operator<=(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(14)
template <class T>
    bool operator>(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(15)
template <class T>
    bool operator>(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(16)
template <class T>
    bool operator>=(const shared_ptr<T>& lhs, std::nullptr_t rhs);
(17)
template <class T>
    bool operator>=(std::nullptr_t lhs, const shared_ptr<T>& rhs);
(18)

Compares two shared_ptr<T> objects or compares shared_ptr<T> with a null pointer.

Having operator< defined for shared_ptr allows shared_ptrs to be used as keys in associative containers, like std::map and std::set.

Contents

[edit] Parameters

lhs - the left-hand shared_ptr to compare
rhs - the right-hand shared_ptr to compare

[edit] Return value

1) lhs.get() == rhs.get()

2) !(lhs == rhs)

3) std::less<V>()(lhs.get(), rhs.get()), where V is the composite pointer type of T* and U*

4) rhs < lhs

5) !(rhs < lhs)

6) !(lhs < rhs)

7) !lhs

8) !rhs

9) (bool)lhs

10) (bool)rhs

11) std::less<T*>()(lhs.get(), nullptr)

12) std::less<T*>()(nullptr, rhs.get())

13) nullptr < lhs

14) rhs < nullptr

15) !(nullptr < lhs)

16) !(rhs < nullptr)

17) !(lhs < nullptr)

18) !(nullptr < rhs)

[edit] Exceptions

noexcept specification:  
noexcept
  (since C++11)

[edit] Example

[edit] See also

returns a pointer to the managed object
(public member function) [edit]