NAME¶

std::unique_ptr::release - std::unique_ptr::release

Synopsis¶

pointer release() noexcept; (since C++11)
(constexpr since C++23)

Releases the ownership of the managed object, if any.

get() returns nullptr after the call.

The caller is responsible for cleaning up the object (e.g. by use of get_deleter()).

Parameters¶

(none)

Return value¶

Pointer to the managed object or nullptr if there was no managed object, i.e. the
value which would be returned by get() before the call.

Example¶

// Run this code

#include <cassert>
#include <iostream>
#include <memory>

struct Foo
{
Foo() { std::cout << "Foo\n"; }
~Foo() { std::cout << "~Foo\n"; }
};

// Ownership of the Foo resource is transferred when calling this function
void legacy_api(Foo* owning_foo)
{
std::cout << __func__ << '\n';
// [legacy code that no one understands or dares touch anymore]
// [...]
delete owning_foo;
}

int main()
{
std::unique_ptr<Foo> managed_foo(new Foo);
// [code that might return or throw or some such]
// [...]
legacy_api(managed_foo.release());

assert(managed_foo == nullptr);
}

Output:¶

Foo
legacy_api
~Foo

See also¶

get returns a pointer to the managed object
(public member function)
get_deleter returns the deleter that is used for destruction of the managed object
(public member function)
reset replaces the managed object
(public member function)