Smart pointers

[OneEyeMan]

Hi,
I was told that my code will be greatly simplified if I start using smart pointers available in C++11. However, it is kind of hard for me to get the syntax.

In the old way I simply write:

std::vector<Foo *> m_myVector;
m_myVector.push_back( new Foo( <constructor_parameter_list> ) );

How it will convert using the new syntax?

Thank you.

[2kaud]

std::vector<unique_ptr<Foo>> m_myVector;
m_myVector.push_back(make_unique<Foo>(<constructor_parameter_list>));

For a compilable example consider

	using Foo = int;

	std::vector<std::unique_ptr<Foo>> m_myVector;
	m_myVector.push_back(make_unique<Foo>(20));

	std::cout << *m_myVector.back() << std::endl;

you'll also need to include <memory>

For more info see https://en.cppreference.com/w/cpp/memory

when m_myvector goes out of scope, all the memory used by the unique_ptr's will be freed automatically.


Note that a unique_ptr can't be copied - only moved. If you need a smart pointer that can be copied use shared_ptr and make_shared().

[wolle]

How it will convert using the new syntax?

Something like this,

	#include <memory>
//
	class Foo {};
//
	std::vector<std::shared_ptr<Foo>> m_myVector;
//
	m_myVector.push_back(std::make_shared<Foo>(/* <constructor_parameter_list> */));

The C++ type usually referred to as "smart pointer" is called std::shared_ptr.

std::make_shared is a convenience function that's often used to create std::shared_ptr<> objects.