Defined in header <memory>
template< class Pointer = void, class Smart, class... Args >
auto out_ptr( Smart& s, Args&&... args );
(since C++23)

Returns an out_ptr_t with deduced template arguments that captures arguments for resetting by reference.

The program is ill-formed if construction of the return value (see below) is ill-formed.


s - the object (typically a smart pointer) to adapt
args... - the arguments for resetting to capture

Return value

std::out_ptr_t<Smart, P, Args&&>(s, std::forward<Args>(args)...), where P is.

  • Pointer, if Pointer is not same as void,
  • otherwise, Smart::pointer, if it is valid and denotes a type,
  • otherwise, Smart::element_type*, if Smart::element_type is valid and denotes a type,
  • otherwise, std::pointer_traits<Smart>::element_type*.


Users may specify the template argument for the template parameter Pointer, in order to interoperate with foreign functions that take a Pointer*.

As all arguments for resetting are captured by reference, the returned out_ptr_t should be a temporary object destroyed at the end of the full-expression containing the call to the foreign function, in order to avoid dangling references.

Feature-test macro Value Std
__cpp_lib_out_ptr 202106L (C++23)


See also

creates an inout_ptr_t with an associated smart pointer and resetting arguments
(function template)
creates a unique pointer that manages a new object
(function template)
creates a shared pointer that manages a new object
(function template)

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