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

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

Variadic functions

Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=

optional, any and variant (C++17)

optional

any

variant

in_placein_place_typein_place_indexin_place_tin_place_type_tin_place_index_t

Pairs and tuples

pair

tuple (C++11)

apply (C++17)

make_from_tuple (C++17)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

integer_sequence (C++14)

Swap, forward and move

swap

exchange (C++14)

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

Elementary string conversions

to_chars (C++17)

from_chars (C++17)

chars_format (C++17)

Type operations

declval (C++11)

as_const (C++17)

 

Dynamic memory management

Smart pointers unique_ptr (C++11) shared_ptr (C++11) weak_ptr (C++11) auto_ptr (until C++17) owner_less (C++11) enable_shared_from_this (C++11) bad_weak_ptr (C++11) default_delete (C++11) Allocators allocator allocator_traits (C++11) allocator_arg_t (C++11) allocator_arg (C++11) uses_allocator (C++11) scoped_allocator_adaptor (C++11) pmr::polymorphic_allocator (C++17) Memory resources pmr::memory_resource (C++17) pmr::get_default_resource (C++17) pmr::set_default_resource (C++17) pmr::new_delete_resource (C++17) pmr::null_memory_resource (C++17) pmr::synchronized_pool_resource (C++17) pmr::unsynchronized_pool_resource (C++17) pmr::monotonic_buffer_resource (C++17) pmr::pool_options (C++17)

Uninitialized storage uninitialized_copy uninitialized_fill uninitialized_move (C++17) uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) destroy (C++17) uninitialized_copy_n (C++11) uninitialized_fill_n uninitialized_move_n (C++17) uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17) destroy_n (C++17) destroy_at (C++17) raw_storage_iterator (deprecated since c++17) get_temporary_buffer (deprecated since c++17) return_temporary_buffer (deprecated since c++17) Garbage collection support declare_reachable (C++11) undeclare_reachable (C++11) declare_no_pointers (C++11) undeclare_no_pointers (C++11) pointer_safety (C++11) get_pointer_safety (C++11) Miscellaneous pointer_traits (C++11) addressof (C++11) align (C++11) C Library malloc aligned_alloc (C++17) calloc realloc free Low level memory management

 

std::unique_ptr

Member functions

unique_ptr::unique_ptr

unique_ptr::~unique_ptr

unique_ptr::operator=

Modifiers

unique_ptr::release

unique_ptr::reset

unique_ptr::swap

Observers

unique_ptr::get

unique_ptr::get_deleter

unique_ptr::operator bool

unique_ptr::operator*unique_ptr::operator->

unique_ptr::operator[]

Non-member functions

make_unique (C++14)

operator==operator!=operator<operator>operator<=operator>operator>=

std::swap

std::hash

 

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.

Parameters

x, y

-

unique_ptrs to compare

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)

Example

Run this code

#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

See also

get	returns a pointer to the managed object (public member function)