table of contents
std::pmr::operator==,std::pmr::operator!=(3) | C++ Standard Libary | std::pmr::operator==,std::pmr::operator!=(3) |
NAME¶
std::pmr::operator==,std::pmr::operator!= - std::pmr::operator==,std::pmr::operator!=
Synopsis¶
Defined in header <memory_resource>
template< class T1, class T2 >
bool operator==( const std::pmr::polymorphic_allocator<T1>& lhs,
(1) (since C++17)
const std::pmr::polymorphic_allocator<T2>& rhs ) noexcept;
friend bool operator==( const polymorphic_allocator& lhs, (2)
(since C++17)
const polymorphic_allocator& rhs ) noexcept;
template< class T1, class T2 >
(since C++17)
bool operator!=( const std::pmr::polymorphic_allocator<T1>& lhs,
(3) (until C++20)
const std::pmr::polymorphic_allocator<T2>& rhs ) noexcept;
friend bool operator!=( const polymorphic_allocator& lhs, (4)
(since C++17)
const polymorphic_allocator& rhs ) noexcept; (until C++20)
Compares two polymorphic allocators. Two polymorphic allocators compare equal
if
their underlying memory resource compares equal.
1) Returns *lhs.resource() == *rhs.resource()
2) Same as (1), allowing conversion to polymorphic_allocator.
This function is not visible to ordinary unqualified or qualified lookup, and
can
only be found by argument-dependent lookup when
std::pmr::polymorphic_allocator is
an associated class of the arguments.
3) Returns !(lhs == rhs)
4) Same as (3), allowing conversion to polymorphic_allocator.
This function is not visible to ordinary unqualified or qualified lookup, and
can
only be found by argument-dependent lookup when
std::pmr::polymorphic_allocator is
an associated class of the arguments.
The != operator is synthesized from operator==. (since C++20)
Parameters¶
lhs, rhs - polymorphic allocators to compare
Return value¶
1-2) *lhs.resource() == *rhs.resource()
3-4) !(lhs == rhs)
Defect reports
The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.
DR Applied to Behavior as published Correct behavior
LWG 3683 C++17 polymorphic_allocator could not be compared overload added
with types convertible to it
2022.07.31 | http://cppreference.com |