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

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< cpp‎ | memory‎ | shared ptr
Revision as of 23:14, 31 May 2013 by P12bot (Talk | contribs)

 
 
 
 
 
Compare two shared_ptr objects
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)
Compare a shared_ptr with a null pointer
template< class T, class U >
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.

Note that the comparison operators for shared_ptr simply compare pointer values; the actual objects pointed to are not compared. Having operator< defined for shared_ptr allows shared_ptrs to be used as keys in associative containers, like std::map and std::set.

Contents

Parameters

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

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)

Exceptions

noexcept specification:  
noexcept
  

Example

See also

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