Man, that is absolutely crazy! Honestly, the more i learn about C++ the more i want to learn about the language, it's like you're fighting a Hydra, you cut one head but two grow as a replacement. I know these things aren't actually easy to get, and since there are like an infinite ammount of things you can do with this language, sometimes it just makes the programmer's life harder. But i think that this just shows that C++ is all about giving control to the programmer to do basically anything he wants to do, which i find it to be fascinating in it's own way. I'm aware that you won't read this comment since this video has been out for a long time, but i seriously am grateful you made this huge ass playlist bro! It's really really helping me to learn this language Thanks bro!
Dude you're so good at explaining stuff. I was trying to understand function pointers for so long and all it took was this video. Also really good job on the threading video. Keep it up!
Another nice use-case of function pointers could be system calls in OS development. You can talk about how the operating system stores an array of function pointer corresponding to each system call and that helps calling functions simply by indexing in that array.
Your videos are absolutly amazing! You mix it up! Most youtubers just make you stare at a console through the whole course, and they only use their cursor to explain things. This playlist is well put together and well worth my time. Keep up the good work
i love that you give a real useful example! ive seen bucky's videos and he never does this. he just tells you the idea and i guess assumes you know when to apply it. great job!
bucky's tutorials are way better. cherno overcomplicates things. there's nothing hes done here that cant be done with just normal functions so he hasn't demonstrated on why u NEED to use function pointers.
This is the greatest coding tutorial series iIve ever seen. If only somebody as talented and knowledgeable about the subject would make similar styled tutorials for other coding languages, the world would be a much better place
I think what makes you so much better than everyone else is the fact that you give examples of where you would actually use all the things you teach in code.
Function pointers were the precursors to OO. On rare occasion, I still use function pointers ( for dll support) , but really, you should avoid them when they are not necessary, not just because of the obtuse syntax, but because they are too loose - which means intractable bugs. I have seen people essentially reinvent c++ using #define and function pointers. I'm sure they thought it was really clever, but they were the only people willing to maintain the code. As soon as they leave the project, the first thing that happens is others toss their unmaintainable garbage code into the bit bucket and start over.
This brought back memories... I remember back in the early 2000 when I added a console to my game engine and hooked up function pointers to strings to be able to call those functions from the console :P
Function pointers allow us to use the concept of higher order function map, if the map function is too complex, then lambda functions won't be readable. So I think that function pointers are still an important part of C++.
I like your videos, sometimes I just need a quick look into a subject and don't have the time to read the technical reference pages. So I just crank your videos double speed and blast my brain. :D thnx
A function and a pointer to the function are different types. When assign a function to a variable, func converts itself to a pointer implicitly, just as you mentioned. On the other hand, we can use a ptr to a func to "interact" with "operator ()" just as func itself, just because the "()" is overloaded implicitly, I guess. Actually, a function is able to be "quoted" by reference with the original type rather than a pointer. But when you want to store several functions to a array to do a batch call, the pointers are stored.
Your videos are amaizing, I was struggling with pointers and function pointers on my faculty projects and your tutorials made my life easier. Thanks and keep doing the good work.
i personally love function pointers. I regulary store them in hashmaps , to call a similar, but different funktion every time. Like when i create elements of some sort, but the functions are only similiar in theory, but the execution is different, even if the result is the same. And at this point, i create a HashMap, calling the functions by keyword, with needed parameters. Thats so cool, it really helps me keep my functions organized, and i can add another element to the Map easily at any point For example when i want to parse Network data from another program, or via Rest APIs
I learned a similar thing in GameMaker and used for Finite State Machine, where state function is assigned to a variable that is called each game frame.
Great content! I was trying to write a homework and couldn't understand what I was doing wrong. after this video I could fix it immediately. VERY HELPFUL THANK YOU
Passing functions is super useful sometimes. It's a concept I first saw using JavaScript. It's really cool that you can do it in C++ (for a while) now.
Man have been coding for a while, even that passing function inside another function using function pointer is sort of a overkill but yeah that's a way and can be used. I am majorly from a C background and mostly in my code we have seen the function pointer array but this was next level, the lambda is not known to me much, will go through and understand it.
I've been working with UE4 and dispatchers seem to work based on function pointers, but I was never sure what a function pointer _was_ or how it was _written_ because UE code is so....'nebulous' isn't the right word, it's just kinda hard to track stuff down is all. And this video got me caught up. A+ stuff right here.
I have always struggled with pointers but this video actually turned on a lightbulb for me XD. I know function pointers are different but the "pointer theory" if you will makes much more sense now!
You should probably just use typedefs. So, if you had, let's say, a button class with an onclick event: typedef void(*ClickEvent)(int x, int y); class Button { public: ClickEvent onclick; } Then you could set each individual button's onclick by setting the onclick member directly: someButton.onclick = [ ] (int x, int y) { //some code here }; or: void clickHandler(int x, int y) { //some code here } someButton.onclick = &clickHandler;
That last bit blew my mind haha. main() calls ForEach which then runs a for loop and "calls" the lambda function which then revisits the for loop can calls the lambda again etc. To make matters worse - ForEach could then still return a value. Lol. Thanks for making my brain hurt Cherno
If it hurts your brain to look at it, then it's usually bad code. I will say, brain hurt is not uncommon when dealing with templates, but it's a necessary pain.
Would be nice to include example with a class member function as well! There’s a couple tricky details to attend to in that case (non static class member function)
I had a tough google session but I managed to figure out how it works. A video would be great tho. There needs to be more on the internet about this subject. 👍
@TheChernoProject I've never seen that kind of for loop! I kinda understand what it does: for (every index in : this array) do this; I'd like to see what other ways that could be used! Could you do a short video, or dedicate part of a video to explaining that. If you've already done that, can you show me where to look? :) Thanks for the vids, they're so helpful
This code is wrong, there is guarantee that 's_Finished' will be read again within the 'DoWorker', while the 'std::cout' does enough for it to likely have caused a memory barrier for it to work and also enough for the compiler to not optimize out the read. Before anyone says using volatile will fix this, volatile does not give any memory barriers, its just going to ensure the data was written or read by the compiler
"So instead of this kind of weird code..." - hahahaha! Yeah to those coming to C++ from C# or Java (or the like) or newbie programmers, I suspect that you are correct. For us old-school C programmers though function pointer syntax such as you illustrated is trivial to our eyes. In that world I am somewhat of an outlier because I happen to know C++ as well. That said, we do what I call "poor man's OO programming" in the sense that we combine data and methods into structs, where "methods" are function pointers that are initialized during some type of "create" invocation, which is a poor-man's rough equivalent of a constructor. The methods (function pointer lists) are grouped into what we call a "method table", then through macros those functions which are assigned to the corresponding function pointers, which are veiled as "methods" are invoked directly by the user, which gives the appearance OO style programming, though not really. Kinda. Anyway I digress. Thank you for the late night chuckle. lol Good video, keep up the work!
noob question, why do u have '&' after const std::vector is it because you are taking the param as reference and not value? but why if you are not changing the variable? sorry if the questions sounds dumb, I'm just trying to learn
Man, that is absolutely crazy!
Honestly, the more i learn about C++ the more i want to learn about the language, it's like you're fighting a Hydra, you cut one head but two grow as a replacement. I know these things aren't actually easy to get, and since there are like an infinite ammount of things you can do with this language, sometimes it just makes the programmer's life harder.
But i think that this just shows that C++ is all about giving control to the programmer to do basically anything he wants to do, which i find it to be fascinating in it's own way.
I'm aware that you won't read this comment since this video has been out for a long time, but i seriously am grateful you made this huge ass playlist bro! It's really really helping me to learn this language
Thanks bro!
Someone give this man a medal, pls.
By far the best videos on C++. Thanks man! You just taught me overnight what my professor couldn't in 7 weeks.
Who else is binge watching the playlist?
yup.
me!
only you, I'm just looking for some specific stuff
Mememememe
> Netflix
Dude you're so good at explaining stuff. I was trying to understand function pointers for so long and all it took was this video. Also really good job on the threading video. Keep it up!
A+++++ content! I've been wanting to learn more about function pointers.
It's C++, not A+++++.
@Louarn he meant grade: A+++++
@@richardlighthouse5328 It was a joke
Now on to function objects, and functors!
needs more +'s
Another nice use-case of function pointers could be system calls in OS development. You can talk about how the operating system stores an array of function pointer corresponding to each system call and that helps calling functions simply by indexing in that array.
Your videos are absolutly amazing! You mix it up! Most youtubers just make you stare at a console through the whole course, and they only use their cursor to explain things. This playlist is well put together and well worth my time. Keep up the good work
i love that you give a real useful example! ive seen bucky's videos and he never does this. he just tells you the idea and i guess assumes you know when to apply it. great job!
bucky's tutorials are way better. cherno overcomplicates things. there's nothing hes done here that cant be done with just normal functions so he hasn't demonstrated on why u NEED to use function pointers.
@@reenamola2162 cherno goes into proper detail, Bucky just scratches the surface
Hey dude, just wanted to let you know you are my go to for getting foundations of principles. You've helped me out several times. Thanks so much!
5 years later, his videos are doing the same for me.
This is the greatest coding tutorial series iIve ever seen. If only somebody as talented and knowledgeable about the subject would make similar styled tutorials for other coding languages, the world would be a much better place
I think what makes you so much better than everyone else is the fact that you give examples of where you would actually use all the things you teach in code.
Function pointers were the precursors to OO. On rare occasion, I still use function pointers ( for dll support) , but really, you should avoid them when they are not necessary, not just because of the obtuse syntax, but because they are too loose - which means intractable bugs. I have seen people essentially reinvent c++ using #define and function pointers. I'm sure they thought it was really clever, but they were the only people willing to maintain the code. As soon as they leave the project, the first thing that happens is others toss their unmaintainable garbage code into the bit bucket and start over.
Found your c++ series now. To learn C++ and dive in quickly your videos are absolute great!
This brought back memories... I remember back in the early 2000 when I added a console to my game engine and hooked up function pointers to strings to be able to call those functions from the console :P
Very few people do such an excellent job at this. Thank you Cherno! :)
This is like when you are half way through the semester and half the class dropped out or changed major.
i just want to see how many are left in the end
Probably the best c++ tutor on youtube
best c++ tutorials, thanks man
Function pointers allow us to use the concept of higher order function map, if the map function is too complex, then lambda functions won't be readable. So I think that function pointers are still an important part of C++.
I like your videos, sometimes I just need a quick look into a subject and don't have the time to read the technical reference pages. So I just crank your videos double speed and blast my brain. :D thnx
A function and a pointer to the function are different types. When assign a function to a variable, func converts itself to a pointer implicitly, just as you mentioned. On the other hand, we can use a ptr to a func to "interact" with "operator ()" just as func itself, just because the "()" is overloaded implicitly, I guess.
Actually, a function is able to be "quoted" by reference with the original type rather than a pointer. But when you want to store several functions to a array to do a batch call, the pointers are stored.
I just realized this is how callback function works. Amazing!
Jesssss.......How incredible channel full of C++ special content.Thankyou very much.It's hard to find something like you here in my classroom....
Your videos are amaizing, I was struggling with pointers and function pointers on my faculty projects and your tutorials made my life easier. Thanks and keep doing the good work.
with this we can implement map(), reduce(), filter() functions as well.
That explanation at 1:04 just clicked in my head and I didn’t even watch the rest of the video. Thanks brotha 🙏🏾
Every time I want to know something about modern c++, I come here. Good job Cherno!
Dude. Your explanations are saving my life right now!
i personally love function pointers.
I regulary store them in hashmaps , to call a similar, but different funktion every time.
Like when i create elements of some sort, but the functions are only similiar in theory, but the execution is different, even if the result is the same.
And at this point, i create a HashMap, calling the functions by keyword, with needed parameters. Thats so cool, it really helps me keep my functions organized, and i can add another element to the Map easily at any point
For example when i want to parse Network data from another program, or via Rest APIs
I learned a similar thing in GameMaker and used for Finite State Machine, where state function is assigned to a variable that is called each game frame.
The best C++ explanations EVER!
Thanks!
finally a channel whose videos i dont have to watch at 1.5x or 2x
Dude, you make me feel more exited about computer science
The name says it all. It points towards a function instead of a variable.
"Gentle introduction" lol 😆
Awesome explanation. I did search a lot but couldn't understand. But now all my doubts are clear after watching this video. Great content.
Great content! I was trying to write a homework and couldn't understand what I was doing wrong. after this video I could fix it immediately. VERY HELPFUL THANK YOU
Such a great explanation with examples.
Love your videos! Helping me a lot with my university stuff!
This is very handy matter in C++. I can pass a pointer as a parameter, pointer to function which I want to be in charge of handling values. :D
this lesson which involves some many technical things such us auto, vector, typedef, function pointer, reference, even iterator inside
Start a data structure series please, greetings from Texas
That helped me so much in writing my own game engine with glut window and opengl
I know it's a bit late, but GODDAMN THAT HAIRCUT MAN!!!!! Everyone looks good with a fade and part
Passing functions is super useful sometimes. It's a concept I first saw using JavaScript. It's really cool that you can do it in C++ (for a while) now.
Man have been coding for a while, even that passing function inside another function using function pointer is sort of a overkill but yeah that's a way and can be used.
I am majorly from a C background and mostly in my code we have seen the function pointer array but this was next level, the lambda is not known to me much, will go through and understand it.
Thanks for making these videos, they really help a lot!
Thank you so much!! I was revising cpp and I got stuck here. This really helped me a bunch. Definitely subscribing!
OMG!
did i just learnt lamda and function pointer in 10 minutes... awesome!
excellent video. well explained. function pointers seem useful but the way I've been exposed to them so far only highlights the confusion!
Really good tutorial. Thx from China ❤
Thank you Cherno for this super fantastic explanation!
I've been working with UE4 and dispatchers seem to work based on function pointers, but I was never sure what a function pointer _was_ or how it was _written_ because UE code is so....'nebulous' isn't the right word, it's just kinda hard to track stuff down is all.
And this video got me caught up. A+ stuff right here.
Keep up the good work. TH-cam need experience coders like you.
Man, it's awesome, thank you so much for these lessons ♥
I have always struggled with pointers but this video actually turned on a lightbulb for me XD. I know function pointers are different but the "pointer theory" if you will makes much more sense now!
He's so cute, makes learning C++ that much better lol.
Brilliant content. I can't thank you enough, Cherno!
Thank you for cool vids. Plz don't stop.
finally i understand why there is need for function pointers!!
thank you .
Thank you!! You just saved me and my assignment from the due date
The simple explaination makes it very helpful! :) Thank you for this series and keep going like you do.
super informative. thanks man
GUI benefits greatly from event driven patterns.
void(*onclick)(int x, int y);
If nobody uses this syntax, what is my alternative?
You should probably just use typedefs. So, if you had, let's say, a button class with an onclick event:
typedef void(*ClickEvent)(int x, int y);
class Button {
public:
ClickEvent onclick;
}
Then you could set each individual button's onclick by setting the onclick member directly:
someButton.onclick = [ ] (int x, int y) { //some code here };
or:
void clickHandler(int x, int y) { //some code here }
someButton.onclick = &clickHandler;
I respect you dude
Im so in love with u that u continue this series
mate i fucking love your series
I just find this so cool
Bro you're a fantastic teacher! thanks a lot!
In C# i use Action for function pointers. Function pointers are great for Publish/Subscription type of projects.
That last bit blew my mind haha. main() calls ForEach which then runs a for loop and "calls" the lambda function which then revisits the for loop can calls the lambda again etc. To make matters worse - ForEach could then still return a value. Lol. Thanks for making my brain hurt Cherno
If it hurts your brain to look at it, then it's usually bad code. I will say, brain hurt is not uncommon when dealing with templates, but it's a necessary pain.
@@eventhisidistaken his code was merely demonstrative. So doesnt really matter if it's "good" or "bad"
@@gvcallen It's demonstrative of what *not* to do.
There's std::for_each ... which can take a function object *with* state, but not just a function-pointer.
Thank you so much !! Great Teacher !!
Would be nice to include example with a class member function as well! There’s a couple tricky details to attend to in that case (non static class member function)
Would you be able to explain the details?? I haven't had much luck looking an answer up. Running into issue with this exact problem.
@@Raul-vg3wt I’ll try to post an example this weekend (crunching this week)
I had a tough google session but I managed to figure out how it works. A video would be great tho. There needs to be more on the internet about this subject. 👍
wow
A Programmer with awesome video quality that doenst use a Mac
I appreciate that
C++ Callbacks! Nice
Great as usual 🔥
Amazing video! Helped me understand better
@TheChernoProject I've never seen that kind of for loop! I kinda understand what it does: for (every index in : this array) do this; I'd like to see what other ways that could be used! Could you do a short video, or dedicate part of a video to explaining that. If you've already done that, can you show me where to look? :) Thanks for the vids, they're so helpful
Thanks for your video!
This code is wrong, there is guarantee that 's_Finished' will be read again within the 'DoWorker', while the 'std::cout' does enough for it to likely have caused a memory barrier for it to work and also enough for the compiler to not optimize out the read.
Before anyone says using volatile will fix this, volatile does not give any memory barriers, its just going to ensure the data was written or read by the compiler
Because we are in C++, it makes sense to see how this works with member functions. Thats why i am actually here but i don't see it.
you should do a video about using variadic templates function pointers, its a really cool topic.
Cool mister. A good explanation.
.... in the future...
Just kidding. I find your series extremely useful.
thank you
Great content. Thank you cherno
Good work ! I need this video , it's awesome !
Thanks for demystifying subject
Showing functional (trailing return) style might give another way to think of it : auto (*foo)( int ) -> void;
Thank you so much for showing new tricks.
very good explanation
Great video, again !!! Thanks !!!!
I always enjoy your video.
"So instead of this kind of weird code..." - hahahaha! Yeah to those coming to C++ from C# or Java (or the like) or newbie programmers, I suspect that you are correct. For us old-school C programmers though function pointer syntax such as you illustrated is trivial to our eyes. In that world I am somewhat of an outlier because I happen to know C++ as well. That said, we do what I call "poor man's OO programming" in the sense that we combine data and methods into structs, where "methods" are function pointers that are initialized during some type of "create" invocation, which is a poor-man's rough equivalent of a constructor. The methods (function pointer lists) are grouped into what we call a "method table", then through macros those functions which are assigned to the corresponding function pointers, which are veiled as "methods" are invoked directly by the user, which gives the appearance OO style programming, though not really. Kinda. Anyway I digress. Thank you for the late night chuckle. lol Good video, keep up the work!
I was always undef the impressiom that there has to be some kind of OO even in procedual languages, thanks for the insights
coming from JavaScript and feeling very much at home, except not with the syntax.
@@kamilkarwacki9590 Yeah. Actually oop languages uses functions pointers in objects.
object.action() is the same >> function_action(&struct)
Great job!
The life savior
noob question, why do u have '&' after const std::vector
is it because you are taking the param as reference and not value?
but why if you are not changing the variable?
sorry if the questions sounds dumb, I'm just trying to learn
also, shouldn't the & sign be before the name of the param and not after the type or is it the same?
I hope that you'll talk about method pointers in the next video and how you can use them without the standard library.