std::out_ptr_t<Smart,Pointer,Args...>::operator Pointer*,std::out_ptr_t<Smart,Pointer,Args...>::operator void**

From cppreference.com

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros(C++20)
Language support library
Concepts library(C++20)
Diagnostics library
Memory management library
Metaprogramming library(C++11)
General utilities library
Containers library
Iterators library
Ranges library(C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library(C++17)
Concurrency support library(C++11)
Execution control library(C++26)
Technical specifications
Symbols index
External libraries

[edit]

Memory management library

voidify

(exposition only*)

Allocators

allocator
allocator_traits (C++11)
allocation_result (C++23)
scoped_allocator_adaptor (C++11)
pmr::polymorphic_allocator (C++17)

allocator_arg (C++11)
uses_allocator (C++11)
uses_allocator_construction_args (C++20)
make_obj_using_allocator (C++20)
uninitialized_construct_using_allocator (C++20)

Uninitialized memory algorithms

uninitialized_copy
uninitialized_fill
uninitialized_move (C++17)
uninitialized_copy_n (C++11)
uninitialized_fill_n
uninitialized_move_n (C++17)
construct_at (C++20)

uninitialized_default_construct (C++17)
uninitialized_value_construct (C++17)
destroy (C++17)
uninitialized_default_construct_n (C++17)
uninitialized_value_construct_n (C++17)
destroy_n (C++17)
destroy_at (C++17)

Constrained uninitialized memory algorithms

ranges::uninitialized_copy (C++20)
ranges::uninitialized_fill (C++20)
ranges::uninitialized_move (C++20)
ranges::uninitialized_copy_n (C++20)
ranges::uninitialized_fill_n (C++20)
ranges::uninitialized_move_n (C++20)
ranges::construct_at (C++20)

ranges::uninitialized_default_construct (C++20)
ranges::uninitialized_value_construct (C++20)
ranges::destroy (C++20)
ranges::uninitialized_default_construct_n (C++20)
ranges::uninitialized_value_construct_n (C++20)
ranges::destroy_n (C++20)
ranges::destroy_at (C++20)

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::pool_options (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)

Explicit lifetime management
start_lifetime_as (C++23)
start_lifetime_as_array (C++23)

Types for composite class design
indirect (C++26)
polymorphic (C++26)

Uninitialized storage(until C++20)

raw_storage_iterator (until C++20*)
get_temporary_buffer (until C++20*)

return_temporary_buffer (until C++20*)

Garbage collector support(until C++23)

declare_reachable (C++11)(until C++23)
declare_no_pointers (C++11)(until C++23)
pointer_safety (C++11)(until C++23)

undeclare_reachable (C++11)(until C++23)
undeclare_no_pointers (C++11)(until C++23)
get_pointer_safety (C++11)(until C++23)

Low level memory
management

operator newoperator new[]

operator deleteoperator delete[]

(C++11)

(C++11)

(C++17)

(C++20)

(C++17)

(C++11)

(C++11)

(C++11)

(until C++17*)

(C++11)

(C++17)

(C++26)

(C++26)

enable_shared_from_this

(C++11)

(C++11)

(C++11)

(C++23)

(C++23)

(C++11)

(C++20)

(C++11)

(C++11)

(C++20)

is_sufficiently_aligned

(C++26)

C Library

malloc
calloc
realloc

free
aligned_alloc (C++17)

[edit]

std::out_ptr_t

Member functions
out_ptr_t::out_ptr_t
out_ptr_t::~out_ptr_t
out_ptr_t::operator Pointerout_ptr_t::operator void*
Non-member functions
out_ptr

[edit]

operator Pointer*()constnoexcept;	(1)	(since C++23)
operatorvoid**()constnoexcept;	(2)	(since C++23)

Exposes the address of aPointer orvoid* object to a foreign function which will generally re-initialize it.

1) Converts*this to the address of storedPointer object.

2) Converts*this to the address of avoid* object. This conversion function participates in overload resolution only ifPointer is not same asvoid*, and the program is ill-formed ifPointer is not a pointer type.
The initial value of thevoid* object is equal the value of the storedPointer object converted tovoid*, and any modification to it affects thePointer value used in thedestructor. Accessing thevoid* object outside the lifetime of*this has undefined behavior.

Once one of these two conversion functions has been called on anout_ptr_t object, the other shall not be called on it, otherwise, the behavior is undefined.

[edit]Parameters

(none)

[edit]Return value

1) The address of storedPointer object.

2) The address of thevoid* object that satisfies aforementioned requirements.

[edit]Notes

If the object pointed by the return value has not been rewritten, it is equal tonullptr.

On common implementations, the object representation of everyPointer that is a pointer type is compatible with that ofvoid*, and therefore these implementations typically store thevoid* object within the storage for thePointer object, no additional storage needed:

If the implementation enables type-based alias analysis (which relies on thestrict aliasing rule), a properly alignedstd::byte[sizeof(void*)] member subobject may be used, and both conversion functions return the address of objectsimplicitly created within the array.
Otherwise, aPointer member subobject may be used for both conversion functions, and(2) may directly returns its addressreinterpret_cast tovoid**.

IfPointer is a pointer type whose object representation is incompatible with that ofvoid*, an additionalbool flag may be needed for recording whether(1) (or(2)) has been called.