Never free memory yourself! Do this instead (in modern C++)

Arguably this is the most important video to understand how memory is allocated in C++. Even more, we cover not just how it can be allocated manually but how it allows C++ to be so fast as well as how to do it safely in modern C++.

*We cover*
⏺ What memory management is
⏺ Why garbage collection is not the way to go
⏺ What is stack and how it enables quick allocations and de-allocations of small variables
⏺ Why stack doesn't work well for persistent data
⏺ What is a heap and how it is useful to allocate persistent data
⏺ What issues can we expect with manual memory allocation
⏺ How smart pointers allow allocating memory safely

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🔗 *Links*
⏺ Donald Knuth picture is from Wikipedia

*Contents*
00:00 - Start
00:25 - What is memory management
02:10 - Why C++ is so cool
04:02 - Allocating and freeing memory
05:07 - The stack
06:18 - Stack hands-on example
08:06 - Why not allocate persistent data on the stack
09:42 - The heap
12:37 - Heap hands-on example
13:43 - Issues with manual memory allocation
18:45 - Smart Pointers

Corrections:
8:24 This example has many issues with it: not only this is not _really_ C++ as the dynamically sized C-style arrays are a compiler extension, not part of the language, but it also misses an include for std::byte. This is just to illustrate how we can overwhelm the stack.

#cplusplus #programming #coding #tutorial

[segfault]

About the manual delete, I always get questions from friends about whether they should use delete on a raw pointer they got as a return value from a function inside some old C library, It is all super confusing for beginners. Usually Documentation have it mentioned as "non-owning". It's amazing to see how all over the place each library's cleanup methods are.

[kompila]

How can I not like this video. Thank you Igor.~

[advik-b]

This is quality content, your channel is underrated bro

[Sheeldzy]

I’ve been watching your channel and following along from the start. This video just helped me tie a lot of concepts together. Many thanks, keep it coming!

[alifimtiaj]

Great explanation. Liked and subbed buddy

[pragyandahal]

Amazing content Igor, keep up the good work.

[SanjeevKumar-nmps]

you always deliver a masterpiece related to C++. Thank you so much for sharing your knowledge :)

[Pedro-jjgp]

Very nice video, thank you! What do you use for the code and diagram animations at the end?

[glaubercini]

Great video, however I couldn't figure it out how you change your T-Shirt that fast 😄.

[JoseRomagueraM]

It's great that people got interested by memory management, but I fully disagree with the usage of smart pointers and garbage collectors as a reliable and performant way of managing memory.
Those techniques assumes that every "object" has his own lifetime, witch is fundamentally false: When there's one, there's many. This affects performance because of memory fragmentation and loses capabilities.
I highly recommend the talk of Ryan Fleury about Arena Allocators, it's mindblowing how simple and effective a linear allocator can be. I almost never think about memory management and have all the performance and reliability.

[richardbennett]

Nice, and why did the presenter change shirts at 5:10???

[tirthasg]

Nice explanation! By the way, what font-style, and colour-theme are you using? It looks pleasant to the eye!

[jojify]

Great. Do you have any udemy course in detail for c++. I would like to purchase it

[richardbennett]

Then, he changed it back again at 6:05.

😂😮😅😅😅

[fjhfbuf]

why do a video? why not simple write a nicely written article that people can read at their own leisure, and one where you can correct the numerous issues raised on the cpp subedit

[politejellydragon]

Nah man, RAII is there for a reason. There is no free lunch. It's an indirection that in many cases isn't necessary. Writing a quick free with a null check into a destructor is not hard. Smart pointers are great for some things, but a shared pointer is inefficient and a unique pointer is kind of obsolete in many cases. I think nuance would make this a bit better. They should not be your default move. You should always evaluate your options.