std::unique_ptr<T,Deleter>::release (3) - Linux Manuals

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

NAME

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

Synopsis

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

Releases the ownership of the managed object if any. get() returns nullptr after the call.

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

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

  int main()
  {
      std::cout << "Creating new Foo...\n";
      std::unique_ptr<Foo> up(new Foo());

      std::cout << "About to release Foo...\n";
      Foo* fp = up.release();

      assert (up.get() == nullptr);
      std::cout << "Foo is no longer owned by unique_ptr...\n";

      delete fp;
  }

Output:

  Creating new Foo...
  Foo
  About to release Foo...
  Foo is no longer owned by unique_ptr...
  ~Foo