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std::unique_ptr<T,Deleter>::release

From cppreference.com
< cpp‎ | memory‎ | unique ptr
 
 
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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()).

Contents

[edit] Parameters

(none)

[edit] 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.

[edit] Example

#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

[edit] See also

returns a pointer to the managed object
(public member function) [edit]
returns the deleter that is used for destruction of the managed object
(public member function) [edit]
replaces the managed object
(public member function) [edit]