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operator==,!=,<,<=,>,>=(std::unique_ptr)

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< cpp‎ | memory‎ | unique ptr
Revision as of 15:41, 1 July 2013 by P12bot (Talk | contribs)

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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) [edit]