operator==,!=,<,<=,>,>=(std::experimental::observer_ptr)
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                    < cpp | experimental | observer ptr
                    
                                                            
                    | template<class W1, class W2> bool operator==(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (1) | (library fundamentals TS v2) | 
| template<class W1, class W2> bool operator!=(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (2) | (library fundamentals TS v2) | 
| template<class W> bool operator==(const observer_ptr<W>& p, std::nullptr_t); | (3) | (library fundamentals TS v2) | 
| template<class W> bool operator==(std::nullptr_t, const observer_ptr<W>& p); | (4) | (library fundamentals TS v2) | 
| template<class W> bool operator!=(const observer_ptr<W>& p, std::nullptr_t); | (5) | (library fundamentals TS v2) | 
| template<class W> bool operator!=(std::nullptr_t, const observer_ptr<W>& p); | (6) | (library fundamentals TS v2) | 
| template<class W1, class W2> bool operator<(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (7) | (library fundamentals TS v2) | 
| template<class W1, class W2> bool operator>(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (8) | (library fundamentals TS v2) | 
| template<class W1, class W2> bool operator<=(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (9) | (library fundamentals TS v2) | 
| template<class W1, class W2> bool operator>=(const observer_ptr<W1>& p1, const observer_ptr<W2>& p2); | (10) | (library fundamentals TS v2) | 
Compares the pointer values of two observer_ptrs, or a observer_ptr and nullptr.
1-2) Equality comparison for two 
observer_ptrs3-6) Equality comparison for an 
observer_ptr and nullptr.7-10) Ordered comparison for two 
observer_ptrs[edit] Parameters
| p, p1, p2 | - | observer_ptrs to compare | 
[edit] Return value
1) p1.get() == p2.get()
2) !(p1 == p2)
3-4) !p
5-6) (bool)p
7) std::less<W3>()(p1.get(), p2.get()), where W3 is the composite pointer type of W1* and W2*
8) p2 < p1
9) !(p2 < p1)
10) !(p1 < p2)
[edit] Exceptions
3-6)noexcept specification:  
noexcept
  

