ConsoleApplication.cpp

#include <iostream>

class Foo {
public:
  std::unique_ptr<int> data;

  Foo(int d) {
    data = std::make_unique<int>(d);
    std::cout << "Constructor called" << std::endl;
  };

  Foo(const Foo& other) {
    data = std::make_unique<int>(*other.data);
    std::cout << "Copy constructor called" << std::endl;
  }

  Foo(Foo&& other) noexcept {
    data = std::move(other.data);
    std::cout << "Move constructor called" << std::endl;
  }
};

class Bar {
public:
  Foo foo_;

  Bar(const Foo& foo) : foo_(foo) {}
};

class Baz {
public:
  Foo foo_;

  Baz(Foo foo) : foo_(std::move(foo)) {}
};

int main() {
  std::cout << "Creating foo..." << std::endl;

  Foo foo{ 1 };

  std::cout << std::endl;
  std::cout << "Creating bar..." << std::endl;

  Bar bar{ foo };

  std::cout << std::endl;
  std::cout << "Creating baz..." << std::endl;

  Baz baz{ std::move(foo) };

  return 0;
}

output.txt

Creating foo...
Constructor called

Creating bar...
Copy constructor called

Creating baz...
Move constructor called
Move constructor called